| case,ground_truth "A 30-year-old woman presents with weight loss, heat intolerance, palpitations, and tremors. | |
| Physical exam shows exophthalmos and diffuse goiter. | |
| Lab tests show low TSH and elevated T3/T4.",Graves Disease "A 23-year-old woman presents with fatigue, pallor, and shortness of breath. | |
| Laboratory tests show hemoglobin 8 g/dL, MCV 70 fL, and low serum ferritin. | |
| She reports heavy menstrual bleeding.",Iron Deficiency Anemia "A 60-year-old woman presents with fatigue, polyuria, polydipsia, and blurred vision. | |
| Laboratory tests show fasting blood glucose of 220 mg/dL and HbA1c of 9.2%.",Type 2 Diabetes Mellitus "A 5-year-old child presents with polyuria, polydipsia, weight loss, and fatigue. | |
| Blood glucose is 350 mg/dL and urine shows ketones.",Type 1 Diabetes Mellitus with Diabetic Ketoacidosis (DKA) "A 28-year-old woman presents with butterfly-shaped facial rash, joint pain, and fatigue. | |
| Laboratory tests reveal positive ANA and anti-dsDNA antibodies.",Systemic Lupus Erythematosus (SLE) "A 40-year-old woman presents with fatigue, weight gain, constipation, and cold intolerance. | |
| Physical examination reveals dry skin and delayed relaxation of deep tendon reflexes. | |
| Laboratory tests show elevated TSH and low free T4 levels.",Hypothyroidism (Hashimoto Thyroiditis) "A 19-year-old man presents with excessive thirst, frequent urination, fatigue, and recent weight loss. | |
| Blood glucose is 380 mg/dL, and urine analysis shows ketones. | |
| Arterial blood gas reveals metabolic acidosis.",Diabetic Ketoacidosis (DKA) due to Type 1 Diabetes Mellitus "A 65-year-old man presents with severe chest pain radiating to his back. | |
| Blood pressure is significantly higher in the right arm than the left arm. | |
| CT angiography shows an intimal flap in the ascending aorta.",Aortic Dissection "A 50-year-old man presents with epigastric pain that improves after eating meals. | |
| Endoscopy reveals a duodenal ulcer. | |
| Testing for Helicobacter pylori is positive.",Duodenal Peptic Ulcer Disease "A 32-year-old woman presents with recurrent episodes of wheezing, chest tightness, and shortness of breath. | |
| Symptoms worsen with exercise and exposure to dust. | |
| Spirometry shows reversible airflow obstruction after bronchodilator administration.",Asthma "A 35-year-old man presents with severe pain, redness, and swelling of the first metatarsophalangeal joint. | |
| Serum uric acid levels are elevated. | |
| Joint aspiration reveals needle-shaped negatively birefringent crystals.",Gout "A 48-year-old woman presents with progressive fatigue, pruritus, and jaundice. | |
| Laboratory tests reveal elevated alkaline phosphatase levels. | |
| Anti-mitochondrial antibodies are positive.",Primary Biliary Cholangitis "A 55-year-old man presents with severe epigastric pain radiating to the back, nausea, and vomiting. | |
| Laboratory tests reveal markedly elevated serum lipase and amylase levels. | |
| CT scan shows inflammation of the pancreas.",Acute Pancreatitis "A 30-year-old woman presents with diarrhea, weight loss, and abdominal bloating. | |
| Laboratory tests reveal iron deficiency anemia. | |
| Serologic testing is positive for anti-tissue transglutaminase antibodies.",Celiac Disease "A 19-year-old woman presents with recurrent abdominal pain, diarrhea, and weight loss. | |
| Colonoscopy reveals skip lesions and transmural inflammation.",Crohn Disease "A 28-year-old man presents with fever, painful urination, and purulent urethral discharge. | |
| Gram stain reveals intracellular gram-negative diplococci.",Gonorrhea "A 62-year-old woman presents with progressive memory loss, difficulty performing daily activities, and personality changes. | |
| Brain imaging reveals generalized cortical atrophy.",Alzheimer Disease "A 45-year-old woman presents with fatigue, increased skin pigmentation, weight loss, and dizziness. | |
| Laboratory tests show hyponatremia, hyperkalemia, and low cortisol levels.",Addison Disease (Primary Adrenal Insufficiency) "A 58-year-old man presents with fatigue, pruritus, and dark-colored urine. | |
| Laboratory tests show elevated liver enzymes and positive hepatitis B surface antigen (HBsAg). | |
| Ultrasound reveals mild hepatomegaly.",Chronic Hepatitis B Infection "A 26-year-old woman presents with episodes of palpitations, sweating, and headaches. | |
| Blood pressure is consistently elevated. | |
| Laboratory testing reveals elevated urinary metanephrines.",Pheochromocytoma "A 14-year-old boy presents with excessive bleeding after minor injuries and recurrent joint swelling. | |
| Laboratory studies show prolonged activated partial thromboplastin time (aPTT) with normal PT. | |
| Factor VIII levels are markedly reduced.",Hemophilia A "A 63-year-old woman presents with bone pain, fatigue, and recurrent infections. | |
| Laboratory tests reveal hypercalcemia and elevated serum protein levels. | |
| Bone marrow biopsy shows clonal plasma cells.",Multiple Myeloma "A 30-year-old man presents with sudden onset shortness of breath and sharp chest pain after a basketball game. | |
| Physical examination reveals decreased breath sounds on the right side. | |
| Chest X-ray shows a collapsed right lung.",Spontaneous Pneumothorax "A 37-year-old woman presents with progressive muscle weakness, especially toward the end of the day. | |
| She also reports drooping eyelids and double vision. | |
| Symptoms improve after rest.",Myasthenia Gravis "A 68-year-old man presents with progressive difficulty swallowing solid foods, which later progresses to liquids. | |
| Endoscopy reveals a mass in the lower esophagus. | |
| Biopsy confirms adenocarcinoma.",Esophageal Adenocarcinoma "A 22-year-old woman presents with fever, migratory joint pain, and a new heart murmur. | |
| She reports a recent untreated sore throat. | |
| Laboratory testing reveals elevated antistreptolysin O (ASO) titers.",Acute Rheumatic Fever "A 29-year-old woman presents with fatigue, dark urine, and yellow discoloration of the eyes. | |
| Laboratory tests show elevated indirect bilirubin and low haptoglobin levels. | |
| Peripheral smear reveals spherocytes.",Autoimmune Hemolytic Anemia "A 70-year-old woman presents with sudden shortness of breath and pleuritic chest pain. | |
| Oxygen saturation is 88% on room air. | |
| CT pulmonary angiography reveals a clot in the pulmonary artery.",Pulmonary Embolism "A 16-year-old boy presents with recurrent episodes of wheezing, coughing, and shortness of breath. | |
| Symptoms worsen during exercise and exposure to pollen. | |
| Spirometry demonstrates reversible airflow obstruction.",Bronchial Asthma "A 64-year-old man presents with progressive fatigue, pallor, and shortness of breath on exertion. | |
| Laboratory studies reveal macrocytic anemia and low vitamin B12 levels. | |
| Anti-intrinsic factor antibodies are positive.",Pernicious Anemia "A 48-year-old woman presents with severe fatigue, pruritus, and jaundice. | |
| Laboratory tests reveal elevated alkaline phosphatase and positive anti-mitochondrial antibodies.",Primary Biliary Cholangitis "A 55-year-old smoker presents with persistent cough, weight loss, and blood-streaked sputum. | |
| Chest CT reveals a centrally located lung mass. | |
| Biopsy demonstrates squamous cell carcinoma.",quamous Cell Carcinoma of the Lung (Sclerosing hemangioma) "A 25-year-old woman presents with fatigue, recurrent oral ulcers, and photosensitive skin rash. | |
| Laboratory testing reveals positive ANA and anti-dsDNA antibodies. | |
| Urinalysis shows proteinuria.",Systemic lupus erythematosus "A 72-year-old man presents with progressive difficulty walking, resting tremor, and muscle rigidity. | |
| Neurological examination reveals bradykinesia and a shuffling gait.",Parkinson Disease "A 50-year-old man presents with fatigue, headache, and facial redness. | |
| Laboratory testing shows elevated hemoglobin, hematocrit, and low erythropoietin levels. | |
| Testing reveals a JAK2 mutation.",Polycythemia Vera "A 34-year-old woman presents with episodic finger discoloration when exposed to cold temperatures. | |
| Her fingers turn white, then blue, and finally red upon rewarming.",Raynaud�s phenomenon "A 21-year-old college student presents with fever, sore throat, and enlarged cervical lymph nodes. | |
| Physical examination reveals splenomegaly. | |
| A heterophile antibody (Monospot) test is positive.",infectious mononucleosis "A 45-year-old woman presents with progressive muscle weakness, weight gain, and easy bruising. | |
| Physical examination reveals central obesity, a rounded ""moon"" face, and purple abdominal striae. | |
| Laboratory tests show elevated cortisol levels that fail to suppress with a low-dose dexamethasone suppression test.",Cushing syndrome "A 45-year-old woman presents with dry eyes, dry mouth, and difficulty swallowing dry foods. | |
| Laboratory tests reveal positive anti-SSA (Ro) antibodies.",Sj�gren Syndrome "A 55-year-old woman presents with proximal muscle pain and morning stiffness involving the shoulders and hips. | |
| Laboratory tests reveal an elevated ESR. | |
| Symptoms improve dramatically with low-dose corticosteroids.",Polymyalgia Rheumatica "A 35-year-old man presents with fever, cough, and weight loss. | |
| Chest imaging shows bilateral hilar lymphadenopathy. | |
| Biopsy reveals noncaseating granulomas.",Sarcoidosis "A 70-year-old smoker presents with persistent cough, hoarseness, and weight loss. | |
| Chest CT reveals a mass at the lung apex. | |
| Neurological examination shows ptosis and miosis.",Pancoast Tumor "A 48-year-old man presents with tremor, rigidity, and involuntary writhing movements. | |
| Family history reveals similar symptoms in multiple relatives. | |
| Genetic testing identifies a trinucleotide repeat expansion.",Huntington Disease "A 29-year-old woman presents with recurrent episodes of vertigo, tinnitus, and fluctuating hearing loss.",M�ni�re Disease "A 40-year-old woman presents with episodic facial flushing, wheezing, and diarrhea. | |
| Urinary 5-HIAA levels are markedly elevated.",Carcinoid Syndrome "A 67-year-old man presents with worsening back pain, anemia, and kidney dysfunction. | |
| Laboratory studies reveal elevated serum protein and Bence Jones proteins in urine",Multiple Myeloma "A 40-year-old woman presents with episodic facial flushing, wheezing, and diarrhea. | |
| Urinary 5-HIAA levels are markedly elevated.",Carcinoid Syndrome "A 30-year-old woman presents with fatigue, jaundice, and itching. | |
| Laboratory tests reveal elevated alkaline phosphatase and positive anti-mitochondrial antibodies.",Primary Biliary Cholangitis "A 38-year-old woman presents with fatigue, weight gain, constipation, and cold intolerance. | |
| Physical examination reveals dry skin and a diffusely enlarged thyroid gland. | |
| Laboratory tests show elevated TSH, low free T4, and positive anti-thyroid peroxidase (anti-TPO) antibodies.",Hashimoto Thyroiditis "A 66-year-old man presents with progressive jaundice, dark urine, pale stools, and unintentional weight loss. | |
| CT scan reveals a mass in the head of the pancreas causing biliary obstruction. | |
| Serum CA 19-9 levels are elevated.",Pancreatic Adenocarcinoma "A 27-year-old man presents with recurrent episodes of wheezing, cough, and chest tightness, particularly at night. | |
| Symptoms worsen with exposure to dust and cold air. | |
| Spirometry demonstrates reversible airflow obstruction following bronchodilator administration.", Asthma "A 48-year-old postmenopausal woman (gravida 2, para 2) presented with a 3-month history of brown-yellowish vaginal discharge, fluctuating lower abdominal pain, fever, and progressive abdominal enlargement over 15 years, worsening in the last 5 years. She reported difficulty with defecation and voiding. She had undergone an attempted myomectomy in the past, but removal was aborted due to severe adhesions. There was no relevant drug or family history. | |
| On rectovaginal examination, a smooth, firm pelvic mass was palpated extending to two fingers below the umbilicus, with limited mobility; the cervix could not be visualized or sondaged. Laboratory studies showed an elevated Cancer Antigen 125 level of 115.6 g/dL. | |
| Transabdominal ultrasound revealed a 269 ? 529 mm hypoechoic mass within the uterine cavity, suspected to represent infected hematometra, and a separate 126 ? 106 mm homogeneous solid mass in the left adnexa with a clear border, raising suspicion for an intraligamentary myoma with cystic degeneration or a left ovarian fibroid. | |
| Abdominal and pelvic computed tomography demonstrated a 145 ? 110 ? 146 mm multilocular cystic mass with thick septa and enhancing solid components, clearly demarcated from the uterus and bladder, displacing the uterus to the right superior-lateral side. The uterine cavity was distended with fluid and air forming an air-fluid level. No lymphadenopathy was noted.",schwannoma "A 75-year-old Caucasian woman was admitted with a prosthetic hip infection 10 days after revision surgery. Her medical history included chronic kidney disease (baseline creatinine 130�150 ?mol/L), hypertension, type 2 diabetes, heart failure, chronic obstructive pulmonary disease, and folate deficiency. Home medications included aspirin, bisoprolol, atorvastatin, furosemide, gliclazide, pantoprazole, folic acid, inhaled bronchodilators, and as-needed oxycodone. On admission she began intravenous vancomycin and acetaminophen for pain. | |
| On hospital day 10 she developed drowsiness, confusion, disorientation, and hyperventilation. Examination showed a Glasgow Coma Scale score of 12. Temperature was 36.2�C, blood pressure 145/66 mmHg, pulse 80/min, respiratory rate 24/min, and oxygen saturation 99% on room air. Cardiopulmonary and neurologic examinations were otherwise unremarkable. | |
| Laboratory studies revealed: | |
| - Sodium 142 mmol/L, potassium 3.5 mmol/L, chloride 118 mmol/L, bicarbonate 5 mmol/L | |
| - Blood urea nitrogen 8 mmol/L, creatinine 150 ?mol/L (baseline) | |
| - Hemoglobin 10.0 g/dL, neutrophils 16.5?10^9/L, platelets 485?10^9/L | |
| - Albumin 17 g/L | |
| Arterial blood gas: pH 7.18, pCO2 1.7 kPa, pO2 16.7 kPa, bicarbonate 8.3 mmol/L, base excess �22.7 mmol/L. The corrected anion gap was 25 mmol/L. | |
| Initial evaluations showed lactic acid 0.7 mmol/L, blood ketones <0.2 mmol/L, salicylate <0.4 mmol/L, and unchanged renal function insufficient to explain the degree of acidosis. Serum toxicology, including acetaminophen level, was unremarkable; the osmolar gap was mildly elevated at 21 mOsm/kg. Urine was sent for organic acid analysis.",5-oxoprolinemia "A 48?year?old woman with a history of asthma presented with a 2?day history of right lower?extremity numbness and pain that worsened despite conservative measures. She denied any low back pain. On examination, manual muscle testing of the right tibialis anterior and extensor hallucis longus was 3/5, and gastrocnemius and flexor hallucis longus were 4/5; deep?tendon reflexes were normal. Straight?leg?raising was positive at 70 degrees; the femoral?nerve stretch test was negative. | |
| Plain radiographs showed degenerative scoliosis at L5�S1. Lumbar MRI demonstrated a right?sided disc herniation at L5�S1 without significant nerve?root or cord compression. Initial peroneal?nerve conduction studies revealed a motor conduction velocity of 51.5 m/s. Ankle?brachial indices were decreased (0.78 on the right, 0.73 on the left), but lower?extremity arteriography showed no significant vascular lesions. Based on these findings, she was diagnosed with lumbar disc herniation and treated symptomatically with Neurotropin�. | |
| By day 7, muscle strength nearly normalized, but lateral leg pain persisted. On day 22, pain increased, and by day 26 she developed right foot drop (tibialis anterior, extensor hallucis longus, flexor hallucis longus, and peroneus longus 1/5; left side 4/5) with absent Achilles reflexes bilaterally. Urgent MRI showed no new nerve?root compression. Repeat peroneal conduction studies failed to elicit an evoked myogenic potential. On day 30, she was unable to walk and was admitted for further evaluation.",Eosinophilic granulomatosis with polyangiitis "A 56-year-old man presented with a 2-month history of bitemporal hemianopia and left labial numbness. On examination, he had visual impairment, bitemporal hemianopia, and right abducens nerve palsy. Laboratory studies showed: TSH 0.658 ?U/mL, free thyroxine 0.41 ng/dL, growth hormone 0.62 ng/mL, LH < 0.2 mIU/mL, FSH < 1.0 mIU/mL, prolactin 19.7 ng/mL, cortisol 0.5 ?g/dL, ACTH 16.4 pg/mL, testosterone < 5.0 ng/dL, and IGF-1 119 ng/mL (?0.73 SD), consistent with hypopituitarism. Dynamic pituitary stimulation tests confirmed gonadotropin, thyroid, and adrenal axis deficiencies and severe GH deficiency. Serum IgG4 was elevated at 319 mg/dL (normal 4.8�105), with a normal total IgG of 1284 mg/dL (IgG4/IgG ratio 0.25). | |
| Pituitary MRI demonstrated diffuse swelling of the pituitary body and stalk, a 7-mm poorly enhancing mass in the right anterior lobe, loss of the posterior pituitary bright spot on T1-weighted images, and thickening of the sphenoid sinus mucosa. Chest CT revealed a nodular lesion in the left lung field, raising suspicion for systemic IgG4-related disease. No other organ involvement was identified on systemic imaging. | |
| Given the combination of hypopituitarism, elevated IgG4 levels, and imaging findings, the patient underwent endoscopic transnasal surgery of the pituitary gland for definitive diagnosis.",IgG4-related hypophysitis "A 40-year-old previously healthy man was admitted after 1 week of progressive apathy, unresponsiveness, and immobility. He became bedridden and required a feeding tube and urinary catheter. On transfer, he was in a vegetative state. | |
| Vital signs: temperature 36.5 �C, heart rate 80 bpm, blood pressure 135/78 mmHg, Glasgow Coma Scale 7 (E3 V1 M3). Pupils 3.5 mm, briskly reactive; corneal reflexes present. Both axial and appendicular muscles were rigid, with flexed arms and extended legs; bilateral Babinski and Chaddock signs were positive. | |
| Laboratory studies: WBC 3.79?10^9/L, neutrophils 74%, CRP 6.07 mg/L, ESR 21 mm/h; HIV, syphilis, hepatitis B and C serologies negative; ANA, anticardiolipin, ANCA, and T-spot negative. Liver and renal functions were normal. | |
| Lumbar puncture: opening pressure 50 mmH?O; CSF clear, protein 3.64 g/L, glucose 2.6 mmol/L (blood glucose 5.38 mmol/L), chloride 123 mmol/L, leukocytes 0/mm?. CSF India ink stain and bacterial cultures were negative. CSF oligoclonal bands, AQP4, MOG, and GFAP antibodies were negative; CSF fungal cultures were negative. | |
| Imaging: Brain CT showed a hypodense lesion in the corpus callosum. MRI revealed a homogeneous mass in the corpus callosum body, hypointense on T1, isointense on T2 FLAIR, with rim enhancement and surrounding vasogenic edema on postcontrast T1. DWI demonstrated rim hyperintensity but no central restricted diffusion.",cryptococcoma "A 68-year-old man with pseudophakic bullous keratopathy underwent Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) in the right eye. His postoperative course was initially uneventful under topical and systemic corticosteroids. He had a history of an eye infection by Thaumetopoea pityocampa (pine processionary) 9 months before DSAEK, which had resolved prior to surgery. | |
| Two months after DSAEK, he was referred for evaluation of keratitis in the right eye. On examination: | |
| � Best-corrected visual acuity was 20/200 in the right eye and 20/20 in the left eye. | |
| � Pupils were isocoric and isoreactive without an afferent pupillary defect. | |
| � There was no pain with ocular movements. | |
| � Slit-lamp biomicroscopy of the right eye showed brown, multilobular lesions confined to the deep corneal stroma, with no conjunctival hyperemia, no discharge, and no epithelial defect. | |
| � The anterior chamber was deep and clear. Intraocular pressure and fundus examination were normal. The left eye was unremarkable. | |
| Anterior segment optical coherence tomography of the right eye revealed a central infiltrate involving all corneal layers and a peripheral infiltrate concentrated in the deep stroma.",Exophiala xenobiotica keratitis "A 27-year-old gravida 2 para 0 woman with an uncomplicated spontaneous pregnancy was referred at 36 weeks� gestation for suspected fetal renal anomalies. Prenatal ultrasound showed: | |
| � Bilateral renal enlargement and hydronephrosis | |
| � A markedly dilated fetal bladder | |
| � A left perirenal fluid collection measuring 64 ? 34 mm that displaced the left kidney anteriorly; the collection contained multiple light bands, flocculent echoes, and slightly echogenic material | |
| � Oligohydramnios | |
| An emergency cesarean delivery produced a male infant (weight 2530 g) with Apgar scores of 8, 8, and 10 at 1, 5, and 10 minutes. His vital signs were stable, and physical examination was normal. Blood and urine routine studies were unremarkable, but serum creatinine was elevated at 156.1 �mol/L, indicating impaired renal function. | |
| On postnatal MRI, the left perirenal collection demonstrated mixed long and short T1 and T2 signals with internal light bands. Magnetic resonance urography revealed bladder wall irregularity and thickening, bilateral ureteral dilation, and urinary retention.",Wunderlich syndrome "A 55-year-old man underwent right hemicolectomy for moderately differentiated adenocarcinoma of the ascending colon, staged as IIIB (T4N1M0). He had no thrombophilic disorders. Preoperative carcinoembryonic antigen (CEA) and CA19-9 levels were normal. He completed six months of adjuvant chemotherapy. Thirteen months after surgery, follow-up CT revealed a 25 mm lesion in segment 8 of the liver. | |
| On readmission, hepatitis B and C serologies were negative. Tumor markers including CEA, CA19-9, ?-fetoprotein, and PIVKA-II were all within normal limits. | |
| CTA demonstrated a liver tumor with two components: a solid portion that enhanced in the early phase and washed out in the delayed phase, and a cystic component. CTAP showed absence of the right portal vein and a perfusion defect throughout the right lobe, suggestive of portal vein tumor thrombus. | |
| Endoscopic retrograde cholangiography showed no communication with the biliary tree, and bile cytology was negative for malignancy. | |
| For preoperative diagnosis, an echo-guided biopsy was performed.",Liver metastasis from colon cancer "A previously healthy 16-year-old female presented with severe back and abdominal pain and multiple episodes of vomiting. She reported intermittent back pain over the prior week, worsened on the day of presentation, accompanied by epigastric pain. On examination, she was afebrile with normal blood pressure and heart rate. The abdomen was soft with mild diffuse tenderness, without peritoneal signs; costovertebral angle tenderness was absent, but palpation elicited left-sided back pain. Initial laboratory evaluation showed a hemoglobin of 12.4 g/dL, a white-cell count of 8000 cells/mL, and a normal urine dipstick. | |
| Renal ultrasound revealed a 13.5-cm cystic lesion in the pelvis and right-sided hydroureteronephrosis, likely due to ureteral compression. Contrast-enhanced CT of the abdomen and pelvis confirmed the large pelvic cyst, most consistent with a mesenteric or duplication cyst, and demonstrated swirling of the mesenteric vessels about the superior mesenteric artery and vein, consistent with a �whirlpool� sign.",chylolymphatic mesenteric cyst "A 49-year-old woman presented with a 2-day history of productive cough with blood-tinged sputum, pleuritic chest pain, and dyspnea. Four months earlier, she had been treated for a lung infection. She had no history of tuberculosis or bronchial asthma, no smoking history, and no recurrent childhood chest infections. On examination, she was in distress with a heart rate of 104 beats/min, respiratory rate of 30 breaths/min, temperature 36.8 �C, blood pressure 130/85 mmHg, oxygen saturation 86% on room air, and a BMI of 33.5 kg/m2. Chest auscultation disclosed crackles in the left posterior upper lung field without wheezes, precordial abnormalities, or peripheral edema. Laboratory studies showed a leukocyte count of 12 ? 103/mm3 with an absolute neutrophil count of 7.8 ? 103/mm3; other biochemistry results were normal. A chest radiograph revealed hyperlucency in the left upper lobe, initially described as oligemia. The electrocardiogram showed sinus tachycardia and T-wave inversions in leads V1�V3. The Wells score for pulmonary embolism was in the moderate-risk range.",Swyer�James�Macleod syndrome "An 18-year-old African male with no prior medical history presented first with a 2-day history of tonsillitis and a new macular rash on his chest that extended to his arms. Three days later he developed abdominal cramping and multiple episodes of non-bloody, watery diarrhea without nausea or vomiting, along with fevers and joint pains in his wrists, elbows, and knees. Initial outpatient care included oral chlorhexidine, lozenges, and symptomatic treatment. | |
| He was then seen at a local health facility with high fever, tachycardia, and within 24 hours became confused with rising serum creatinine (from 200 to 400 ?mol/L). He received ceftriaxone, paracetamol, loperamide, and one dose of IV methylprednisolone, but continued to deteriorate and was transferred to our hospital. | |
| On arrival he was febrile (40�C), hypotensive (70/40 mmHg), tachycardic (130 bpm), tachypneic (50 breaths/min), and hypoxemic (SaO2 86% on room air). GCS was 14/15. Lung exam revealed bilaterally coarse crepitations; cardiovascular exam an audible S3 gallop; abdomen distended and tense with hypoactive bowel sounds; musculoskeletal exam was normal. He received fluid resuscitation, central line placement, and norepinephrine at 0.4 ?g/kg/min. | |
| Laboratory data showed: WBC 27.1?10^9/L; Hb 10.9 g/dL; platelets 281?10^9/L; procalcitonin 71.6 ng/mL; CRP 287 mg/L; creatinine 494 ?mol/L; urea 26.7 mmol/L; Na 128 mmol/L; K 4.87 mmol/L; HCO3� 15.5 mmol/L; blood gas pH 7.33, PCO2 23 mmHg, PO2 122 mmHg, HCO3� 19.8 mmol/L. Liver tests showed AST 1461 U/L and ALT 812 U/L; hepatitis A, B, C, and HIV screens were negative. Urinalysis had 3+ protein and 4+ blood without RBCs; urine albumin:creatinine ratio was 52.3 mg/mmol. Cardiac markers were elevated (troponin 17 137 ng/mL; CK > 7800 U/L). | |
| A negative ASOT made rheumatic fever unlikely. Chest X-ray showed pulmonary edema and cardiomegaly; echocardiogram revealed dilated cardiomyopathy with EF 30�35% and normal valves. Abdominal CT demonstrated a distended bowel with splenic and renal infarcts. HRCT confirmed cardiomegaly with bi-basal atelectasis. Initial differentials included bacterial septic shock, vasculitis (antiphospholipid syndrome or medium-sized vessel vasculitis), and multisystem inflammatory syndrome. | |
| He required intubation and increasing norepinephrine (0.7 ?g/kg/min), meropenem, vancomycin, urgent dialysis, and cooling measures. An autoimmune panel showed low C3 (0.51 g/L) and C4 (0.04 g/L), and he received a low-dose steroid pulse (250 mg IV daily). Autoantibodies returned with a positive beta2-glycoprotein IgA antiphospholipid antibody and negative ANA, anti�dsDNA, ENA, pANCA, and cANCA. SARS-CoV-2 PCR from tracheal aspirate and nasal swab was negative.",Multisystem inflammatory syndrome in children "A 28-year-old woman presented with a 2-year history of hip pain following low-impact falls. Initial imaging revealed stress fractures of the left rib, left sacrum, and left femoral neck. Laboratory studies showed an elevated alkaline phosphatase level of 220 U/L (reference range, 30�95), a phosphorus level of 2.1 mg/dL (2.5�5.0), creatinine 0.56 mg/dL, and 25-OH vitamin D 14.8 ng/mL (30�95). Outpatient evaluation demonstrated 1,25[OH]2D3 <8 pg/mL (18�72), calcium 9.3 mg/dL, albumin 4.28 g/dL, parathyroid hormone 37.9 pg/mL, ferritin 16.9 ng/mL, 24-hour urine phosphorus 0.5 g (0.3�1.3 g), urine creatinine 0.9 g/24 h (1�2 g/24 h), thyroid-stimulating hormone 2.54 mIU/L, and fibroblast growth factor 23 (FGF23) 1241 RU/mL (<180). Bone densitometry showed Z-scores of ?2.5 in the lumbar spine and ?1.9 in the femoral neck, and an octreotide scan was negative. She was treated with calcitriol and phosphate and underwent percutaneous pinning of the femoral neck. She became pregnant; her phosphate and calcitriol were adjusted to maintain normal phosphorus levels, and genetic evaluation for hypophosphatemic disorders, including X-linked hypophosphatemia, was unremarkable. Family history was negative for bone disease. After a planned cesarean delivery, she continued to have disabling bilateral hip, knee, and ankle pain. On re-presentation, examination revealed a slow gait with a limp and lumbar tenderness. Current labs on calcitriol 0.5 mcg daily and elemental phosphorus 500 mg twice daily included alkaline phosphatase 204 U/L, phosphorus 1.6 mg/dL, 25-OH vitamin D 32 ng/mL, 1,25[OH]2D3 32.4 pg/mL, calcium 9 mg/dL, albumin 4.2 g/dL, and parathyroid hormone 74 pg/mL. Phosphate supplementation was increased to three times daily, raising the phosphorus level to 2.3 mg/dL. A gallium-68 DOTATATE PET/MRI showed a 9?8-mm intracortical lesion in the anterolateral right fibular head (standard uptake value [SUV], 65), with additional uptake in a right femoral neck stress fracture (SUV, 5.6) and bilateral calcaneal stress fractures (SUV, 4).",Tumor-induced osteomalacia "A 22-year-old woman presented for evaluation of malaligned teeth. On examination, all permanent teeth had erupted except the third molars in both arches and the lower left lateral incisor. There was mild spacing between the lower left central incisor and the canine. She had Class II, Division 1 malocclusion with crowding in the maxillary anterior region. There was no history of prior dental extractions. | |
| A panoramic radiograph and a mandibular occlusal film showed an unerupted lower left lateral incisor with an associated well-defined radiopaque lesion in the left mandibular anterior region, surrounded by a thin radiolucent halo, which appeared to obstruct the eruption path of the tooth.",Compound odontoma "A 76-year-old woman noted a slowly enlarging mass adjacent to her right lateral malleolus over 3 months, causing discomfort with shoes and walking. She denied trauma or infection. On examination, there was a firm, 4 cm retromalleolar mass without overlying skin changes or regional lymphadenopathy and no sensorimotor deficits. | |
| Standard ankle radiographs showed only soft-tissue swelling, with no osteolysis. Ultrasound revealed a solid, heterogeneous, multilobulated mass measuring 40 ? 29 mm within Kager�s fat pad, between the Achilles and peroneal tendons, with moderate superficial vascularity on Doppler. | |
| CT of the ankle demonstrated bone edema of the posterior talar process, a focal lateral talocrural arthropathy, moderate joint effusion, and mechanical synovitis. | |
| MRI confirmed a well-delineated fibrous tissue lesion in the posterolateral soft tissues of the ankle measuring 40 ? 33 ? 42 mm, abutting the Achilles tendon and peroneal retinaculum. There was no intralesional hemosiderin. The lesion showed heterogeneous progressive enhancement without washout.",desmoplastic fibroblastoma "A 20-year-old man with no significant medical history presented for evaluation before orthognathic surgery. On oral examination, there was a 1.5-cm diameter, exophytic, smooth, regular, and soft lesion on the midline of the dorsal tongue. The patient reported that the lesion had been present since birth and had not changed in size or character. Vital signs were within normal limits. An MRI of the tongue showed a 1.5-cm protuberant mass arising from the dorsal aspect of the tongue in the midline at the junction of the oral component and base; the lesion appeared partly fatty, likely submucosal, demonstrated mild contrast enhancement, had intact overlying mucosa, and showed no involvement of intrinsic tongue muscles. The sublingual space and major salivary glands appeared normal.",leiomyomatous hamartoma "A 53-year-old man presented with a 3-year history of slowly progressive lower urinary tract symptoms, including nocturia two to three times per night and a slow urinary stream. Urinalysis showed microscopic hematuria (3�5 red cells per high-power field). He had no history of lichen sclerosis, sexually transmitted infection, pelvic radiation, genitourinary trauma, or family history of genitourinary malignancy. Renal ultrasonography findings were normal. Flexible cystourethroscopy revealed a circumferential urethral mass concerning for urothelial carcinoma, and biopsy specimens were negative for carcinoma but demonstrated amyloid protein deposition. Examination of the external genitalia was unremarkable, with no palpable induration along the ventral penile shaft. A systemic evaluation for amyloidosis revealed no additional disease manifestations. Retrograde urethrography showed an approximately 2-cm segment of stenosis in the penile urethra.",LocalizedUrethralAmyloidosis "An 82-year-old man with epithelioid pleural mesothelioma (cT1N0M0) was treated with ipilimumab and nivolumab. After eight courses, follow-up chest CT showed new bilateral infiltrative shadows. He reported fever and dyspnea. Laboratory tests revealed elevated C-reactive protein and surfactant protein D levels; Krebs von den Lungen-6 was normal. Sputum cultures, procalcitonin, and SARS-CoV-2 PCR were negative. Serologic testing for anti�nuclear antigen, anti�aminoacyl�tRNA synthetase, anti-cyclic citrullinated peptide, anti-Sj�gren�s-syndrome-related antigen A and B, and anti-neutrophil cytoplasmic antigen antibodies were all negative. He had no history of antigen exposure. Immunotherapy was discontinued. He received lascufloxacin and then tazobactam/ceftolozane without improvement; oxygen requirement increased to 2 L/min. Based on the clinical picture and imaging, grade 3 ICI-induced pneumonitis was suspected. He underwent methylprednisolone 1000 mg/day for 3 days followed by prednisolone 60 mg/day for 8 days, but chest radiographs remained unchanged and oxygen needs rose to 4 L/min. A second course of methylprednisolone 1000 mg/day for 3 days produced no clinical improvement. One week later, bronchoscopy showed no airway secretions. Bronchoalveolar lavage fluid contained 29% neutrophils, 58% lymphocytes, 13% macrophages, and a CD4/CD8 ratio of 0.33. Transbronchial lung biopsy showed no malignancy, and cultures of bronchoscopy specimens were negative. Based on these findings, he was diagnosed with steroid-refractory ICI-induced pneumonitis.",immune-related pneumonitis "A 63-year-old woman with a history of hypertension presented with persistent chest and back pain. Two months earlier, she noted chest discomfort and dyspnea on exertion that gradually worsened. On arrival, her electrocardiogram showed sinus rhythm with diffuse ST-segment depression and ST elevation in lead aVR, along with occasional premature ventricular complexes. Laboratory studies revealed an elevated cardiac troponin I level of 620 pg/mL. Transthoracic echocardiography demonstrated diffuse hypokinesis of the left ventricle. A contrast-enhanced CT scan was obtained to investigate the cause, which showed a 6.3 cm?4.5 cm?5.5 cm cystic mass above the left atrium; on noncontrast images the mass had heterogeneous attenuation (15�56 Hounsfield units) and it exhibited slight contrast enhancement. Shortly after the CT, the patient developed transient cardiogenic shock that responded to noradrenaline support.",Schwannoma "A 76-year-old woman with a history of appendicitis, torsion of an ovarian cyst pedicle, and uterine myoma presented with a rapidly enlarging right parietal mass behind the ear over one month. She had no neurological deficits or systemic symptoms. Laboratory studies, including complete blood counts, metabolic panel, and viral serology for HIV and Epstein-Barr virus, were all normal or negative. Noncontrast CT of the head revealed a 5-cm hyperdense meningeal mass with parietal bone invasion. Gadolinium-enhanced MRI showed a heterogeneously enhancing lesion in the right parietal region. Cerebral angiography demonstrated a vascular tumor supplied by the middle meningeal artery. Thus, a clinical diagnosis of osteoblastic meningioma was made, and the differential diagnosis included primary lymphoma, metastasis, and sarcoma. The patient underwent endovascular embolization of the feeding artery followed by surgical resection. Intraoperatively, the tumor was extradural, caused skull destruction, and had no intradural involvement. Histology showed a malignant spindle cell neoplasm with positive immunostaining for ?-smooth muscle actin, vimentin, and desmin, and negative staining for Epstein-Barr virus.",Leiomyosarcoma "A 44-year-old Hispanic woman presented with six months of progressive generalized weakness, a 40-pound weight loss over four months, and two weeks of dyspnea. She had a five-year history of hypertension treated with lisinopril but had been noncompliant for over three years. She denied alcohol, illicit drug use, and was a lifelong non-smoker. | |
| On examination, she appeared ill and wasted, with mucosal pallor and non-tender, rubbery axillary and inguinal lymphadenopathy. There was no skin rash, joint deformities, or peripheral edema. The abdomen was mildly distended but non-tender, without organomegaly. Respiratory examination revealed dullness to percussion and decreased breath sounds at the left lung base. Cardiovascular and neurological examinations were unremarkable. | |
| Initial laboratory findings: | |
| � Hemoglobin 6.6 g/dL, hematocrit 20.9%, platelets 544 ?10^9/L | |
| � White blood cell count 3.5 ?10^9/L (neutrophils 80.4%, lymphocytes 16%) | |
| � Sodium 131 mM/L, potassium 5.7 mM/L, chloride 105 mM/L, bicarbonate 18 mM/L | |
| � Blood urea nitrogen 60 mg/dL, creatinine 1.69 mg/dL | |
| � Urinalysis: trace proteinuria | |
| Chest radiography showed bilateral pleural effusions; thoracentesis revealed an exudative effusion. CT scans of the chest, abdomen, and pelvis and an axillary lymph node biopsy were negative for malignancy. HIV and tuberculin skin testing were negative. | |
| On hospital day 4, she developed acute inflammatory arthritis of the elbows and knees. Serologic tests revealed high titers of ANA, anti�double-stranded DNA, and anti�Smith antibodies, with low complement C3 levels. Urinalysis showed pH 5, 16 WBCs and 27 RBCs per high-power field, and 24-hour urinary protein 0.81 g/day. Her estimated glomerular filtration rate was 53 mL/min/1.73 m^2, and leukopenia recurred on multiple occasions. | |
| On day 5, she experienced worsening dyspnea and pleuritic chest pain. Repeat chest radiography demonstrated reaccumulation of pleural effusions, and echocardiography showed a pericardial effusion. Arterial blood gas and concurrent basic metabolic panel revealed a non�anion gap metabolic acidosis with hyperkalemia (pH 7.34, pCO2 26 mmHg, HCO3� 14 mM/L; Na 145 mM/L, K 5.5 mM/L, Cl 120 mM/L, HCO3� 19 mM/L, BUN 67 mg/dL, creatinine 1.09 mg/dL). Morning serum aldosterone was less than 1 ng/dL.",Type 4 renal tubular acidosis "A 35-year-old woman presented with left fronto-orbital swelling of 10 years� duration. She reported progressive deterioration of vision in her left eye over 1.5 years, to the point where she could barely perceive hand movements near her face. The proptosis had become more pronounced over the past month, and the left globe was displaced inferiorly and medially. There was no history of endocrine abnormalities. | |
| On contrast-enhanced MRI of the brain, there was a heterogeneous enhancing mass in the left orbital roof displacing the globe anteriorly and inferolaterally. An axial CT scan showed an expansive lytic bony lesion involving the superior and lateral walls of the orbit, including the orbital roof, frontal bone, and sphenoid wing.",Fibrous dysplasia "A 16-year-old male with no prior medical history noted a small lump in his right hemiscrotum two months earlier during self-examination. He denied any history of scrotal trauma or inflammation, and the lump�s size remained unchanged over two months. He experienced only mild discomfort during exercise, which resolved with rest. On physical examination, there was a painless, round, hazelnut-sized mass localized to the tail of the right epididymis; the testicles and groin were otherwise unremarkable. Scrotal ultrasonography demonstrated a solid, well-demarcated, hyperechoic, hypoperfused 1.3 ? 1.1 cm mass at the tail of the right epididymis containing two small hypoechoic foci, with no invasion of adjacent structures. Routine blood tests, coagulation profile, and serum tumor markers (AFP, LDH, CEA, and ?-HCG) were all within normal limits.",adenomatoid tumor "A 64-year-old woman presented with a slowly enlarging mass in the left labia majora over 10 years. Her vital signs were normal. On examination, the mass was firm, painless, immobile, and measured approximately 7 ? 4 cm, extending toward the mons pubis. Routine laboratory tests were normal. | |
| Surgical history: | |
| � In 2000, a mass in the Bartholin�s gland was excised; histopathology in 2007 showed chondroid syringoma. | |
| � One year later, a recurrence in the labia majora was resected; histology showed clear cell hidradenoma (�lobular glandular proliferation of cuboid cells with no anaplasia�). | |
| � Most recently, ultrasound revealed a 4.2 ? 8 cm heterogeneous, hypervascular subcutaneous mass; CT scan demonstrated a 3.8 ? 7.2 cm heterogeneous, contrast-enhancing lesion in the left labia majora extending to the anterior perineum, and a low-density focus in the liver suggestive of a simple cyst. | |
| � The vulvar mass was excised; on gross examination it measured 7 ? 3 ? 4 cm, was gray and well-circumscribed, and was reported again as chondroid syringoma. | |
| Three months later, the patient noted another recurrence near the fourchette. The lesion was excised and submitted for histopathologic evaluation.",AdenoidCysticCarcinoma "A previously healthy young man presented during a month of religious fasting with a 1-week history of intractable vomiting, postprandial upper abdominal pain, and bloating. He had been compliant with fasting customs, was markedly lean, and reported progressive inability to tolerate oral intake. On examination, he was dehydrated and exhausted. After initial resuscitation, abdominal ultrasonography and plain radiographs showed marked gastric distension. A nasogastric tube was placed for decompression. Contrast-enhanced CT of the abdomen revealed compression of the third portion of the duodenum between the superior mesenteric artery and the aorta at an acute angle. Upper gastrointestinal endoscopy was normal, with no intrinsic luminal lesions.",Superior mesenteric artery syndrome "A 29-year-old woman, with no significant past medical history, was referred for evaluation of multiple intra-abdominal cystic lesions. She reported no acute abdominal pain, weight loss, or fever. On examination her abdomen was soft, with an epigastric fluctuant area; otherwise the physical and systemic examinations were unremarkable. Laboratory studies showed mildly abnormal liver function tests and �a strongly positive hydatid serology.� Abdominal ultrasound demonstrated �a hydatid cyst of segment III of the liver fistulized in the subcutaneous soft tissues measuring 4.19 ? 1.98 cm and continued with another formation measuring 3 ? 2 cm.� Contrast-enhanced abdominal and pelvic CT revealed �multiple hepatic, splenic and peritoneal cystic formations, of which one of the hepatic lesions is fistulized to the wall, the most voluminous being pelvic (40 ? 43 mm), and a cystic umbilical formation (13 ? 10 mm), with the main biliary tract containing dense material with upstream dilatation of 10 mm of hydatid origin, with the presence of aerobilia suggestive of a bilio-digestive fistula.�",Hydatid disease "An 8?year?old boy with no significant past medical history presented with a 30-minute history of generalized abdominal pain followed by a single episode of vomiting. During the event he developed diaphoresis, mucocutaneous paleness, dizziness, dysarthria, incoherent speech, and lack of eye contact, without loss of consciousness, abnormal movements, or sphincter relaxation. The episode lasted 10 minutes, after which he reported a frontal headache (5/10) and persistent nausea. Family denied toxin or medication exposure. He had a similar episode 18 months earlier, diagnosed as migraine. There was no personal or family history of epilepsy or neurological disorders. Developmental milestones were age?appropriate, and he was performing well in school. | |
| On admission, his vital signs were normal except for blood pressure above the 95th percentile for age. Neurologic examination revealed confusion and disorientation; he could not recognize his mother or speak but could follow visual commands. Motor and sensory examinations were normal. Approximately 20 minutes after arrival, his consciousness and orientation improved. Over the next hours he had three additional self?limited vomiting episodes and ongoing headache, which improved after a single IV dose of diclofenac (1?mg/kg). | |
| Complete blood count, serum chemistries, and electrolytes (including sodium, chloride, potassium, magnesium, and phosphorus) were all within normal limits. Brain MRI with an epilepsy protocol was reported as normal for age.",Self-limited epilepsy with autonomic seizures "A 25-year-old nulliparous woman presented with a 1-month history of insidious-onset right lower abdominal pain. She also had lifelong non-pitting edema of the left leg extending to the labia majora. She was otherwise healthy, with regular menses and no tobacco or alcohol use. On examination, she was afebrile, blood pressure was 110/80 mmHg, pulse 88 beats/min, respiratory rate 16 breaths/min, and oxygen saturation 98% on room air. Cardiac and respiratory examinations were unremarkable. Neurologic exam was normal. Abdomen revealed a firm, non-tender, mobile mass measuring approximately 12 cm ? 10 cm in the right lower quadrant; bimanual pelvic examination confirmed a right adnexal mass. | |
| Baseline hematologic, biochemical, thyroid, renal, and HIV/HBV/HCV serologies were within normal limits. Tumor markers were all in the reference range: carcinoembryonic antigen 1.14 ng/mL, lactate dehydrogenase 251 U/L, ?-fetoprotein 2.16 ng/mL, CA-125 21 U/mL, and ?-hCG 2.39 �IU/mL. Pap smear was negative. | |
| Transvaginal ultrasound showed multiple uterine fibroids and a large hypoechoic lesion in the right adnexa. Contrast-enhanced CT of the abdomen and pelvis revealed a well-marginated thin-walled solid-cystic lesion measuring 16.1 ? 7.9 ? 8.1 cm in the abdominopelvic region containing a 2.3 ? 2.1 cm cystic component and a 5.8 ? 5.7 cm solid component. A separate 7 ? 3.2 ? 2.8 cm cystic lesion was noted in the right parauterine region. Bilateral ovaries were not visualized separately. The uterus was bulky with multiple fibroids. Multiple small mesenteric lymph nodes were seen. Incidentally, a double inferior vena cava was identified, with the left cava draining via the left renal vein to the right-sided cava. Serology for filarial infection was negative. | |
| Although tumor markers were normal, the imaging findings were concerning for an ovarian neoplasm. A staging laparotomy with surgical excision was planned, with a provisional diagnosis of a malignant ovarian tumor in the setting of uterine fibroids and unilateral lymphedema.",Massive ovarian edema "A 22-year-old man presented with a 15-day history of generalized painful fluid?filled skin lesions, 7 days of yellow scleral discoloration, and 1 month of fever following removal of a tibial implant. Two years earlier, he had sustained a tibial fracture treated with internal fixation. After implant removal, he developed a surgical-site infection and persistent fever; he initially took paracetamol without relief, then obtained ciprofloxacin over the counter. Two days after starting ciprofloxacin, he developed generalized pruritus that progressed to fluid-filled rashes. He denied angioedema, dyspnea, abdominal distention, lower-limb swelling, hematemesis, melena, altered sensorium, alcohol use, or immunocompromise. | |
| On examination, he was afebrile with stable vital signs. He had icterus but no pallor, clubbing, cyanosis, lymphadenopathy, or dehydration. Systemic examination was unremarkable. Dermatologic examination showed multiple generalized vesicles and bullae with non-hemorrhagic crusts over the trunk and extremities (palms and soles spared). Lesions were tender, with post-inflammatory hyperpigmentation. Mucosal findings included hemorrhagic lip crusts and penile erosion. | |
| Laboratory studies revealed: | |
| � Leukocyte count 18,520/mm3 (neutrophils 64%, lymphocytes 22%, eosinophils 12%) | |
| � Hemoglobin 9.8 g/dL, platelets 423,000/mm3 | |
| � AST 283 U/L, ALT 246 U/L, alkaline phosphatase 1390 U/L | |
| � Total bilirubin 14 mg/dL (conjugated 13.7 mg/dL) | |
| � Albumin 2.4 g/dL, INR 2.7 | |
| � Renal function and electrolytes were within normal limits.",Toxic epidermal necrolysis "A 74-year-old right-handed woman was brought to the psychiatry clinic with a 5-month history of abrupt onset of disorganized speech, severe anxiety, and self-harm behaviors that began after a family trip. Her speech was rapid, fluent, and nonsensical�exemplified by the phrase �Our neighbor has gone to the cobbler to buy Ghormeh Sabzi��consistent with Wernicke�s aphasia. Over the ensuing months, she developed agitation, persecutory delusions, visual and auditory hallucinations, urinary and fecal incontinence, and a persistent urge to flee her home. | |
| Her psychiatric history included a 10-year history of depression treated with sertraline. There was no prior cognitive impairment or neurological disease. On examination, she was disoriented to time, demonstrated anomia, and had marked perseveration on the Clock Drawing Test, impaired performance on Luria�s three-step test, and defective crossed-pentagon drawing. Cognitive testing revealed an MMSE score of 2/30 and an ACE-R score of 2/100, likely confounded by comprehension deficits. | |
| An initial brain MRI performed 2 months after symptom onset was reported as normal. She was diagnosed with Alzheimer�s disease and started on memantine and quetiapine, without clinical improvement. Because of the acute presentation and prominent frontal and temporal features, she was referred to neurology for further assessment.",cerebral venous thrombosis "A 15-year-old male presented with a 4-week history of watery diarrhea (20 episodes per day), vomiting, and diffuse abdominal pain aggravated by spicy foods. He reported an 8-kg weight loss (�15% of body weight). Physical examination revealed brownish macules on the hands and feet, hyperchromic punctate lesions on the trunk, and onychodystrophy. His medical history was notable for cleft lip and palate repair and recurrent diarrheal episodes since childhood. | |
| Laboratory studies demonstrated mild hypoproteinemia and hypoalbuminemia (total protein 3.52 g/dL [normal 6.6�8.3], albumin 2.09 g/dL [3.5�5.2]), zinc deficiency (51 �g/dL [70�120]), low vitamin B12 (<150 pg/mL [300�900]), and otherwise unremarkable blood counts and metabolic panel. | |
| Esophagogastroduodenoscopy showed multiple type II and III Yamada polyps on atrophic gastric mucosa and nodular lymphoid lesions in the duodenum. Colonoscopy revealed numerous sessile and subpedunculated polyps throughout the colon and rectum.",Cronkhite-Canada syndrome "A 13-year-old multiparous Quarter Horse mare at day 332 of gestation was referred for dystocia. Approximately 24 hours before referral, she exhibited intermittent mild colic signs without progression to Stage II labor. The following morning, she was found in lateral recumbency and unwilling to rise. On presentation, the mare was anxious with moderate colic signs, a heart rate of 60 beats/min, respiratory rate elevated, and temperature 38.6 �C. Mucous membranes were hyperemic with a capillary refill time of <1 s. Packed cell volume was 42% and total solids 7.0 g/dL. CBC showed mild leukocytosis (10,000 WBC/�L). Serum chemistry revealed mild hypernatremia (143 mmol/L), hyperchloremia (103 mmol/L), hyperalbuminemia (4.0 g/dL), hyperglycemia (138 mg/dL), mildly elevated GGT (23 U/L), and mild indirect hyperbilirubinemia (1.7 mg/dL). Venous blood gas showed pH 7.42, bicarbonate 18.1 mmol/L, mild hyperlactatemia (1.8 mmol/L), hypocalcemia (5.8 mg/dL), and hypomagnesemia (0.9 mg/dL). | |
| Abdominal palpation per rectum revealed broad ligaments without tension and a firm uterine body; no fetal heartbeat was detected on ultrasound. Vaginal examination showed a 4 cm cervical dilation with serosanguineous malodorous exudate. Digital examination revealed a nonviable fetus in a transverse, head-back position. Given inadequate cervical dilation and malpresentation, controlled vaginal delivery was not viable, and cesarean section was recommended.",UterineBodyConstriction "A 91-year-old woman presented with sudden onset of right upper abdominal pain. She had a history of constipation and osteoporosis, treated with magnesium oxide and eldecalcitol, and underwent endoscopic mucosal resection for early gastric cancer 9 years earlier. On examination, she was tender and distended in the upper abdomen, with rebound tenderness and guarding. Laboratory studies showed a white-cell count of 12.9 ? 10^3/�L and a C-reactive protein level of 5.7 mg/dL; other values were within normal limits. Contrast-enhanced abdominal CT demonstrated ascites, enhancement of the duodenal wall, and free air around the duodenum. Emergency upper endoscopy revealed a perforation in the second portion of the duodenum. She underwent emergency laparoscopic surgery, which showed a perforated area of the duodenal wall wrapped by omentum. After dissecting the omentum, a mass was identified at the perforation site, and the lesion together with the perforation was resected using a linear stapler.",Heterotopic pancreas "An 8-year-old girl was evaluated for recurrent seizures, left-sided weakness, and developmental delays. Seizures began at age 3 months, initially infrequent but progressively more frequent despite antiepileptic therapy. The parents also noted delayed motor and cognitive milestones and gradual behavioral changes, including disturbed sleep, irritability, and episodes of aimless talking. There was no family history of neurological disorders and no reported perinatal complications or trauma. | |
| On neurologic examination, she had significant cognitive impairment and marked left hemiparesis with brisk reflexes, consistent with an upper motor neuron pattern. Sensory examination and cranial nerves were unremarkable. Routine laboratory studies, including metabolic and infectious panels, were normal. Electroencephalography showed focal abnormal brain activity concordant with her seizure semiology. | |
| Brain magnetic resonance imaging demonstrated marked asymmetry of the cerebral hemispheres, with significant atrophy of the right cerebral hemisphere and ex vacuo dilatation of the right lateral ventricle. Ipsilateral calvarial thickening and compensatory hyperpneumatization of the right sphenoid bone and bilateral mastoid air cells were evident. In the right fronto-parieto-temporal region, there were areas of cystic encephalomalacia surrounded by gliosis, suggesting a remote focal brain injury.",Dyke-Davidoff-Masson syndrome "A 52-year-old Bangladeshi man was referred to ENT for a 1-week history of odynophagia and a persistent sensation of a foreign body in his throat following fish-bone impaction. He had presented to the Emergency Department with similar symptoms and was diagnosed with a right tonsillar foreign body. He denied dysphagia, dyspnea, otalgia, or weight loss. His social history was notable for moderate tobacco use and habitual betel-nut chewing. | |
| On examination, there was no visible fish bone. Instead, a protruding lesion was observed through the right palatine tonsil; it was hard, mobile, well-delineated, nontender, and yellowish-white in color. Flexible fibreoptic nasopharyngoscopy showed no mucosal ulceration or mass elsewhere in the upper aerodigestive tract, and no cervical lymphadenopathy was palpable. A lateral neck radiograph revealed no fish bone but demonstrated a uniform, ovoid calcification overlying the right tonsillar region abutting the mandibular ramus.",Tonsillolith "A 36-year-old woman presented with sudden-onset, sharp upper abdominal pain rated 9/10, which awakened her early in the morning. The pain was minimally relieved by oxycodone and worsened with oral intake. She reported associated nausea and vomiting and was unable to tolerate liquids or a soft diet. Three weeks earlier, she had undergone Roux-en-Y gastric bypass for weight management, after which she experienced intermittent nausea. She denied bloating, changes in bowel habits, or urinary symptoms. | |
| Her medical history included type 2 diabetes mellitus managed with pantoprazole, metformin, and semaglutide. She had undergone laparoscopic cholecystectomy, four lower-segment cesarean sections, bilateral salpingectomy, diagnostic hysteroscopy, and endometrial ablation. | |
| On examination, she appeared uncomfortable. There was generalized abdominal tenderness, most pronounced in the right hypochondrium, without peritoneal signs. Her pain was disproportionate to the physical findings. Vital signs were within normal limits: temperature 36.4 �C, heart rate 89 beats/min, respiratory rate 18 breaths/min, and blood pressure 126/88 mm Hg. | |
| Laboratory studies showed hemoglobin 135 g/L, white-cell count 10.5 ? 10^9/L, C-reactive protein < 0.5 mg/L, lactate 1 mmol/L, and normal liver function tests. | |
| Contrast-enhanced abdominal CT demonstrated a cluster of small-bowel loops in the left upper quadrant, positioned anterior to the splenic flexure. The central mesenteric vessels exhibited a spiral (whirl) pattern, with congestion of mesenteric fat and stretching and convergence of vessels. There were no signs of anastomotic leak, strangulation, or bowel obstruction. Differential diagnoses included internal herniation and adhesive bowel obstruction.",Petersen�s hernia "A 44-year-old single man presented with a 10-year history of progressively enlarging perianal and lower scrotal warts. He reported pruritus and a bloody, foul-smelling discharge over the past 4 years. He had a history of smoking, alcohol use, chronic hepatitis B infection, and multiple heterosexual partners. | |
| On examination, he was well-nourished with normal vital signs. There were hard, cauliflower-shaped, circumferential perianal warts sparing a 1 cm bridge at 6 o�clock, and an associated exophytic lesion measuring 22 cm involving the lower scrotal skin. Proctoscopic and per-rectal examination showed no intra-anal involvement. The remainder of the physical examination was unremarkable. | |
| Laboratory studies revealed a white-cell count of 7.2?10^9/l, hemoglobin 12.3 g/dl, platelets 303?10^9/l, normal liver and renal function tests, and normal coagulation parameters. Treponema pallidum hemagglutination and indirect hemagglutination assays were non-reactive. HIV antigen/antibody testing was negative, and hepatitis B surface antigen was positive.",GiantCondylomaAcuminatum "A 56-year-old man with no significant medical history presented with intermittent, vague left-sided abdominal pain of one year�s duration. He denied urinary symptoms, hematuria, or fever. On examination, his abdomen was soft and non-tender. Laboratory studies�including a complete blood count, renal and liver function tests, serum chemistry, and urinalysis�were all within normal limits. Contrast-enhanced CT of the abdomen and pelvis revealed a large exophytic mass in the upper pole of the left kidney measuring 12 ? 11 ? 8.6 cm, appearing heterogeneous and hypodense, with no invasion beyond the renal capsule; these findings were reported as suspicious for renal cell carcinoma. The patient underwent a left robotic radical nephrectomy. Gross examination showed a well-circumscribed, encapsulated 12 ? 11.5 ? 8 cm mass occupying most of the kidney without penetration of the capsule, featuring a lobulated gelatinous/myxoid cut surface and scattered firm white-yellow areas. Histologic sections demonstrated a hypocellular tumor arranged in lobules separated by delicate fibrous strands, composed of bland spindle cells in an abundant myxoid stroma with thin-walled blood vessels and no cellular atypia, lipoblasts, mitotic figures, or necrosis. Immunohistochemical staining revealed diffuse strong positivity for vimentin, patchy positivity for CD34, and negativity for Pan-cytokeratin, desmin, smooth muscle actin, S100, and MUC4. Ki-67 labeling was <1%. FISH analysis for CHOP (12q13) and FUS (16q11.2) rearrangements was negative.",renal myxoma "A 33-year-old man with no significant past medical history presented with a 3-month history of progressively worsening occipital headache, exacerbated by Valsalva maneuvers. On neurologic examination, he had bilateral past-pointing and an intention tremor. Brain MRI revealed a 6.9 ? 5.5 ? 6.1 cm lobulated mass centered at the left cerebellopontine angle, extending craniocaudally from the left ambient cistern to the premedullary space. The lesion involved and expanded Meckel�s cave, with a small extension into the left infratemporal fossa via the foramen ovale. It contained multiloculated T1-hypointense, T2-FLAIR�partially suppressible nonenhancing cystic areas with interspersed enhancing septa, as well as T1/T2-isointense enhancing solid components. Susceptibility-weighted imaging demonstrated curvilinear signal loss with corresponding T1 hyperintensity consistent with hemorrhagic foci, and diffusion-weighted imaging showed no diffusion restriction. There was compression of the left cerebellum and brainstem, dilation of the third, fourth, and lateral ventricles, anterior displacement of the cavernous sinus, and encasement with mild narrowing of the left petrous internal carotid artery; the masticator muscles were preserved. Noncontrast CT of the head showed smooth remodeling and erosion of the left petrous apex, clivus, carotid canal, and foramen ovale, along with two punctate calcifications; the internal auditory canals and inner ear structures were unremarkable.",trigeminal schwannoma "A 28-year-old man was admitted with a 2-day history of intermittent, sharp, central chest pain with diaphoresis. The pain was pleuritic and worsened when he sat forward. He denied recent viral symptoms and had not received a COVID-19 booster. His medical history was significant for ulcerative colitis diagnosed 3 weeks earlier, for which he started mesalazine; his bowel symptoms had improved. He took no other medications and had no allergies. He smoked 3�4 cigarettes daily and denied alcohol or drug use. There was no family history of cardiovascular disease. | |
| On examination he was hemodynamically stable; the only abnormal finding was stage 2 finger clubbing. ECG showed sinus rhythm with benign early repolarization in the anterior leads. Chest radiography was unremarkable. Laboratory tests revealed a hemoglobin concentration of 132 g/L (120�170), a low mean corpuscular volume of 75 fL (80�97), and a high-sensitivity troponin T of 275 ng/L (<14) peaking at 632 ng/L on hospital day 2. C-reactive protein was 59 mg/L (<5) rising to 173 mg/L. Serum viral and autoantibody screens were negative. | |
| Transthoracic echocardiography showed a normal left ventricular size, borderline low systolic function (LVEF 50�55%) with dyssynchronous septal motion, and a normal right ventricle without pericardial effusion. Given his atypical pain, young age, and troponin rise, an invasive coronary angiogram was considered but deferred in favor of cardiac magnetic resonance imaging. | |
| On hospital day 3, CMR demonstrated a normal-sized left ventricle with mild systolic dysfunction (LVEF 59%) and hypokinesia of the anterolateral and inferolateral segments. The basal lateral wall was thickened to 14 mm. The right ventricle was small with normal function. There was extensive patchy late gadolinium enhancement in a mid-wall to epicardial distribution, particularly in the basal and mid lateral wall. T2-weighted imaging suggested myocardial edema despite suboptimal image quality. There was no pericardial enhancement or effusion. These findings were consistent with an extensive inflammatory myocardial process.",mesalazine-induced myocarditis "A 52-year-old man presented with a progressively enlarging, mildly tender right-flank subcutaneous nodule noted over two years. He had a history of HBV-positive hepatocellular carcinoma (HCC) treated with partial hepatectomy, entecavir, transarterial chemoembolization, sorafenib, regorafenib, and pembrolizumab over the preceding two years. On admission, vital signs were: temperature 37.2�C, pulse 112/min, respiratory rate 19/min, blood pressure 114/78 mmHg. He denied alcohol or tobacco use. | |
| Physical examination revealed an ~8?4 cm subcutaneous mass over the right hypochondriac and flank regions; the remainder of the examination was unremarkable. Laboratory studies showed: white blood cell count 8.93?10^3/�l, hemoglobin 13.8 g/dl, AST 55.7 U/l, ALT 55.7 U/l, lactate dehydrogenase 201 U/l, alpha-fetoprotein 157 ng/ml, CEA 7.99 ng/ml, CA19-9 21.6 U/ml, HBsAg reactive, HCV-PCR negative. | |
| Contrast-enhanced CT of the chest revealed multiple bilateral pulmonary nodules. Abdominal CT showed multiple nodules in liver segments 5 and 7 (largest 3.5 cm) and a right-flank soft tissue mass invading the 12th rib measuring 8?4?4 cm. Based on the clinical history and imaging, extrahepatic metastasis of HCC was suspected, but a primary soft tissue sarcoma could not be excluded. After discussion, surgical excision of the flank mass was performed without complications.",hepatocellular carcinoma "A 63-year-old woman was admitted with insidious upper abdominal pain unrelated to food ingestion and nausea, and after an episode of intense acute abdominal pain. She denied hematemesis or melena. Her medical history included untreated dyslipidemia and well-controlled hypertension on methyldopa. She was a smoker of ten cigarettes per day and had no family history of cancer. Physical examination was normal except for a palpable, movable mass in the upper abdomen. Laboratory tests, including a complete blood count, were normal without anemia. Abdominal ultrasound showed a large echogenic mass in the gastric antrum compatible with an expansive lesion. Conventional endoscopy revealed a large submucosal bulging mass in the posterior gastric wall with three Forrest III�type ulcerated areas; biopsy attempts failed to sample the submucosal mass, and ulcer biopsies showed only necrotic mucosa. Contrast-enhanced CT of the abdomen demonstrated a well-defined, homogeneous, oval mass arising from the posterior gastric wall, measuring approximately 10?6?11 cm, compressing the second portion of the duodenum; the lesion had fat-tissue attenuation with central contrast enhancement and trabecular architecture but did not invade the peripheral layers.",Gastric lipoma "A 62-year-old man presented with a two-week history of an asymptomatic swelling in the right lower half of the face and reduced mouth opening. He reported two prior similar episodes over eight years: the first, five years ago, was treated as a buccal-space infection with incision and drainage; the second, two years ago, resolved spontaneously. He had no pain or fever and was a known diabetic on regular medication. | |
| On examination, there was gross right facial asymmetry. Extraorally, a 6 ? 6 cm ovoid subcutaneous swelling extended from the level of the right lateral canthus to 1 cm below the corner of the mouth and from the corner of the mouth posteriorly to the mandibular ramus. The borders were ill-defined, the consistency ranged from soft to firm, and the overlying skin was normal. There was no lymphadenopathy, paresthesia, or facial palsy. Intraorally, the right buccal mucosa was elevated and glistening, with no vestibular obliteration; mouth opening was restricted by the mass. | |
| Contrast-enhanced CT of the face showed a well-defined soft-tissue mass with cystic areas in the right buccal space. Intracystic loculations with dense cystic content were noted, and there was erosion of the posterior buccal cortex without perforation of the maxilla; the maxillary antrum was compressed. | |
| A clinical diagnosis of a nonspecific chronic abscess with buccal-space involvement was made. Under general anesthesia, an intraoral approach was used to excise the lesion in toto with a margin of fibrous tissue. The lesion shelled out easily, with no involvement of buccinator muscle or bone. The excised specimen measured 4.8 ? 4.5 cm, was creamish-brown, firm, irregular, and had a leathery pouch-like appearance, entirely within the soft tissue of the buccal space.",Keratocystic odontogenic tumour "A 41-year-old previously healthy man presented with a 2-year history of progressively worsening fever, weight loss, night sweats, and a dry cough. He also reported chronic lower back pain without neurologic deficits and a painful nonhealing ulcer on his right hallux. He had two sputum GeneXpert tests at local clinics, both negative. He was treated symptomatically with paracetamol, NSAIDs, and topical antibacterials. | |
| On referral for the toe ulcer, examination revealed a cachectic man who was normotensive and afebrile, with no lymphadenopathy or edema. He had tenderness over the thoracic spine but no neurologic deficits. Laboratory tests showed: | |
| � Hemoglobin 10.9 g/dL, white cells 7.3?10^9/L, platelets 369?10^9/L | |
| � ESR >130 mm/hr, CRP 113 mg/L | |
| � IgA 6.2 g/L, anti-DNase B 259 IU/mL | |
| � Negative ANA, anti-dsDNA, ANCA, HIV, hepatitis B and C, and syphilis serologies | |
| � Urine protein-creatinine ratio 0.242 g/mmol; dipstick: 3+ leukocytes, 3+ red blood cells; microscopy: granular casts; urine culture: no growth | |
| Chest radiograph showed bilateral reticular-nodular opacities. An induced sputum was trace positive for MTB on GeneXpert and subsequently grew MTB sensitive to rifampicin and isoniazid. Biopsy of the toe ulcer showed necrotizing granulomatous inflammation with a solitary acid-fast bacillus. MRI of the spine revealed contiguous spondylitis from T6 to T10 with discitis and an epidural/paraspinal collection causing spinal cord compression. Renal ultrasound demonstrated normal-sized kidneys with increased echogenicity.",IgA nephropathy "A 72-year-old man with no prior medical history underwent dual-chamber pacemaker implantation in the left prepectoral area for 2:1 atrioventricular block. The procedure was uneventful, and he was discharged the next day. On postoperative day 4, he presented with fever (38.1�C) and an inflamed, infiltrating, necrotic lesion over the implant site. Laboratory studies revealed an elevated inflammatory syndrome; blood cultures were obtained and antibiotics (amoxicillin�clavulanate, 1 g three times daily) were started empirically. A swab of the lesion grew Staphylococcus epidermidis. By day 7, despite antibiotic therapy, the lesion had darkened and enlarged, and blood cultures remained negative.",Pyoderma gangrenosum "A 69-year-old woman presented with a several-month history of a painless, firm area of induration and mild erythema below her left lower eyelid. Her history included chronic scleritis treated successfully with NSAIDs, left levator resection for ptosis, and a dacryocystorhinostomy one month before the onset of the lesion. The mass persisted despite two courses of antibiotics for presumed postoperative cellulitis. Three months after surgery, the nodule remained stable in size. | |
| On examination, there was a focal, non-tender, indurated elevation along the inferior orbital rim. A CT scan of the orbits demonstrated soft-tissue thickening of the anterior-inferior orbital rim and lower eyelid without extension into surrounding structures or bony invasion. | |
| An excisional biopsy was performed. Intraoperative frozen sections revealed granulomatous inflammation. The final histopathology showed granulomatous inflammation with central necrobiosis, extensive Alcian-Blue positive mucin, and scattered multinucleated giant cells. There was no evidence of malignancy, and bacterial and fungal stains (Ziehl�Neelsen and Grocott) were negative.",granuloma annulare "A 42-year-old man presented with a 1.5-year history of abdominal pain and three loose, watery stools daily. He had gastroesophageal reflux disease and hereditary hemochromatosis (grade 3 iron overload, mild portal fibrosis, C282Y homozygosity). He denied rectal bleeding, fever, or weight loss. Vital signs were normal, and physical examination was unremarkable. | |
| Laboratory evaluation showed negative ova and parasites, bacterial culture, fecal leukocytes, and Clostridium difficile NAAT. Histoplasma antigen, anti-transglutaminase, and anti-endomysial antibodies were negative. Rapid plasma reagin and Tropheryma whipplei testing were also negative. | |
| Colonoscopy revealed erythematous mucosa in the transverse colon and rectum and congestion in the terminal ileum. Esophagogastroduodenoscopy showed diffuse gastric erythema with erosions and duodenitis. Biopsies from the stomach, duodenum, terminal ileum, colon, and rectum all demonstrated non-caseating microgranulomas; acid-fast bacilli and fungal stains were negative, and no Helicobacter pylori organisms were identified. | |
| CT of the abdomen and pelvis showed hepatosplenomegaly; a prior liver biopsy showed no granulomas. Chest CT was unremarkable. Angiotensin-converting enzyme level was elevated at 77 U/L.",Sarcoidosis "A 42-year-old Taiwanese woman was referred for hepatic tumors found incidentally during a routine check?up. She denied abdominal pain, weight loss, or anorexia. Her medical history was negative for liver disease, and she took no regular medications. She smoked 2�5 cigarettes daily for ten years, denied alcohol use, and had no family history of malignancy. On examination, she was afebrile, with no jaundice or lymphadenopathy; the abdomen was soft and non-tender without ascites. Laboratory tests showed WBC 9950/�L, hemoglobin 15.0 g/dL, AST 37 U/L, ALT 82 U/L, total bilirubin 0.6 mg/dL, albumin 3.5 g/dL, alkaline phosphatase 167 U/L, LDH 180 U/L; HBsAg and anti-HCV were negative; AFP, CEA, CA19-9, and CA125 were within normal limits. Tri?phasic contrast-enhanced CT of the abdomen revealed multiple heterogeneous masses in both lobes of the liver, the largest measuring 8.3 cm in segment 4, with uneven arterial enhancement and washout in the portal venous and delayed phases. An ultrasound?guided liver biopsy showed epithelioid tumor cells with moderate nuclear atypia and focal intracytoplasmic melanin pigments in solid nests infiltrating the parenchyma. Immunohistochemical staining revealed diffuse positivity for HMB45, Melan-A, SOX10, and BRAF V600E, with negativity for cytokeratin.",Metastatic melanoma of unknown primary "A 13-year-old boy presented with a 1-year history of pain and swelling around his right ankle that had been gradually increasing in size. On examination, there was bony thickening over the lateral malleolus, and the ankle and subtalar joints had a full range of motion. Complete blood count was within normal limits, and erythrocyte sedimentation rate was 68 mm at the first hour. Plain radiography of the right ankle revealed a submetaphyseal lytic lesion in the distal tibia with a well-defined sclerotic margin. On the basis of these findings, a diagnosis of Brodie�s abscess was made, and curettage was performed under spinal anesthesia via an anterior approach. Curetted material was sent for histopathological and microbiological assessment.",xanthogranulomatous osteomyelitis "A 58?year?old man presented to the emergency department with a 24?hour history of right iliac fossa pain, nausea, and diarrhea. His surgical history was notable for a laparoscopic appendectomy performed 8 months earlier; he had no other significant past medical history. On examination, he was febrile, and his hemodynamic and respiratory parameters were stable. Abdominal palpation elicited pain in the right lower quadrant without peritoneal signs. Laboratory studies showed a white?blood?cell count of 25,000 cells/mm3 with 85% neutrophils and a C?reactive protein level of 180 mg/dL; all other laboratory values were within normal limits. An abdominal CT scan demonstrated a swollen and thickened tubular structure measuring 36 ? 27 mm at the cecal pole, with a 25?mm pericecal collection adjacent to surgical clips.",StumpAppendicitis "A 20-year-old woman presented with a 3-month history of intermittent abdominal pain, recurrent vomiting, and melena. She had no significant past medical history and no family history of cancer. On examination, she had mild abdominal tenderness; gynecological examination was normal. Laboratory studies revealed iron-deficiency anemia; white blood cell and platelet counts were normal. Upper and lower endoscopies were unremarkable. Magnetic resonance enterography demonstrated a focal segment of small-bowel wall thickening measuring 15 mm by 2 mm. An exploratory laparotomy revealed an exophytic ileal mass with mesenteric lymphadenopathy but no peritoneal or hepatic metastases. A wide segmental resection was performed without complication. | |
| Gross examination showed a 30 mm by 25 mm polypoid, tan-white, lobulated mass arising from the small-intestinal wall. Microscopically, the lesion was a transmural, infiltrative proliferation of uniform epithelioid and spindle cells arranged in nested and fascicular patterns, with variable eosinophilic or clear cytoplasm, round to oval vesicular nuclei, inconspicuous nucleoli, and up to 10 mitoses per 10 high-power fields; there was mucosal ulceration but no melanin pigment, lymphovascular invasion, or perineural invasion, and three mesenteric lymph nodes were negative for tumor. | |
| Immunohistochemical analysis showed diffuse, strong positivity for S100 protein and SOX10; HMB45 and Melan A were negative. There was patchy synaptophysin expression. CD117, DOG1, cytokeratin, CD34, smooth muscle actin, desmin, chromogranin, and CD56 were all negative.",Gastrointestinal clear cell sarcoma "A 14-year-old boy presented with a 10-month history of a painful mass in his left knee. The mass began the size of a marble and gradually enlarged to the size of a tennis ball. There was no redness or fever. On examination, the range of motion in the left knee was 0��20�. A complete blood count showed a leukocyte count of 7.7 ? 10^3 per mm^3. Plain radiographs of the knee revealed soft-tissue swelling without bony abnormality. Magnetic resonance imaging demonstrated intermediate signal intensity on T1- and T2-weighted images in the Hoffa pad region, suprapatellar bursa, and popliteal bursa, with areas of low signal intensity suggestive of hemosiderin deposits.",Tuberculous gonitis "A 31-year-old woman presents with a 4-year history of recurrent painful ulcerations on both legs and feet. She has no personal or family history of vascular or autoimmune disease, denies arthralgia or other dermatologic symptoms, and takes no medications. She also denies tobacco or illicit drug use. On examination, a reticular purplish livedo pattern is noted over both lower limbs. Multiple chronic, nonhealing ulcers are present over the lateral malleolus and the dorsum of the left foot, along with white atrophic scars on the lower legs and ankles. Preliminary diagnostic considerations included thrombophilia, hematologic malignancies, immune-mediated vasculitis, connective tissue diseases, arterial disease, vascular proliferations, diabetes, and medication-induced ulcers. A lesional skin biopsy was performed.",Livedoid vasculopathy "A 42-year-old man underwent transthoracic echocardiography as part of a routine medical checkup, which revealed a left ventricular mass. He had no prior medical history and denied fever, weight loss, dyspnea, or other symptoms. On admission, his temperature was 36.5 �C, blood pressure 120/80 mm Hg, and electrocardiogram showed normal sinus rhythm. A chest radiograph revealed no active lung lesions. Transthoracic echocardiography demonstrated a mobile, smooth, oval, pedunculated mass originating from the left ventricular lateral wall, measuring 1.34 ? 1.9 cm. Contrast-enhanced chest computed tomography showed the mass attached to the interventricular septum with focal contrast enhancement.",hemangioma "A 36-year-old woman presented with persistent severe pain on the left side of her face. Two months earlier, on the day after receiving her third dose of the Pfizer-BioNTech COVID-19 vaccine, she experienced episodic sharp, electric-shock�like pain initially affecting the entire left hemiface. Within days, the pain localized to the V2 and V3 distributions of the left trigeminal nerve. Attacks lasted 4�5 seconds, were triggered by jaw movement during eating or tooth brushing, and reached 10/10 on a numeric pain scale. She reported allodynia to cold air and hypersensitivity to touch in the affected area. During attacks, she described distorted sensations in the V2 region, but sensory testing was otherwise normal. She had no other neurological deficits, no relevant past medical or family history, and prior doses of the same vaccine had been uneventful. Routine laboratory tests, including D-dimer, were normal. RT-qPCR for SARS-CoV-2 and other infections was negative. Contrast-enhanced MRI of the head showed no abnormalities.",Trigeminal neuralgia "A 62-year-old woman presents with 24 hours of fever, left-sided flank pain, and foul-smelling urine. Five years earlier she underwent bilateral lung transplantation for severe chronic obstructive pulmonary disease (FEV1 15%). Her past medical history is notable for hypertension and a 70�pack-year smoking history. Immunosuppressive therapy consists of prednisone and tacrolimus; mycophenolate mofetil was discontinued for leukopenia. Prophylactic antimicrobial therapy includes trimethoprim�sulfamethoxazole, itraconazole, and valganciclovir (continued for detectable CMV viremia). On examination she is febrile but otherwise unrevealing. Laboratory studies show a leukocytosis of 20,000 per �L (neutrophils 18,150 per �L) and hyponatremia (122 mEq/L). Urinalysis is positive for leukocyte esterase, nitrites, and white blood cells. Blood and urine cultures grow Escherichia coli; she is initially treated with vancomycin and piperacillin�tazobactam and then de-escalated to ceftriaxone. CT of the abdomen and pelvis reveals a non-obstructing right nephrolithiasis and irregular, nodular thickening of the bladder wall, suspicious for neoplasm.",Post-transplant lymphoproliferative disorder "A 69-year-old Japanese man presented with pain and a 10-mm polypoid mass on the left lower gingiva. He had undergone chemoradiotherapy 15 years earlier for squamous cell carcinoma of the left buccal mucosa, with no recurrence until now. He denied tobacco or alcohol use. On examination, vital signs were normal; trismus was present. Intraoral inspection revealed a rough-surfaced polypoid lesion in the left lower molar gingiva covered by a whitish pseudomembrane. Panoramic radiography showed a moth-eaten pattern of mandibular bone resorption. Contrast-enhanced CT demonstrated an enhancing soft-tissue mass with irregular mandibular bone destruction. A biopsy specimen showed loose granulation tissue with scattered atypical spindle and pleomorphic cells in a fibrin-rich edematous stroma alongside inflammatory cells. The overlying squamous epithelium exhibited only slight nuclear enlargement without dysplasia. The spindle cells had basophilic cytoplasm, bizarre nuclei, and atypical mitoses; many contained neutrophils within cytoplasmic vacuoles. Immunohistochemical staining revealed that the spindle cells were positive for vimentin, ?-smooth muscle actin, p63, p53, and CD68, but negative for pan-cytokeratin and other epithelial markers; Ki-67 labeling index was approximately 50%. These findings prompted consideration of a malignant spindle cell process.",Spindle cell squamous cell carcinoma "A 40-year-old woman presented to the emergency department with a 2-day history of abdominal pain and vomiting. She reported no passage of gas or stool during this period and denied fever. Four years earlier, she underwent a hysterectomy via a Pfannenstiel incision and had experienced intermittent abdominal discomfort since. On examination, her vital signs were stable. Abdominal palpation revealed an 8-cm mass in the epigastric region. Laboratory studies demonstrated leukocytosis; other values were within normal limits. A plain abdominal radiograph showed air�fluid levels in several small-bowel loops and multiple opaque linear densities in the midline. Contrast-enhanced CT of the abdomen revealed a 107 ? 60 mm mass among small-bowel loops at the L2�L4 level, closely related to the anterior abdominal wall, with peripheral contrast enhancement and linear metallic hypodense artifacts within its right aspect.",Gossypiboma "A 49-year-old man presented with left testicular bloating and dull pain for 20 years, acutely worsening over the past 10 days. He denied other medical history. On examination, the left testis was enlarged, firm, smooth, without discrete nodules or tenderness, and transillumination was negative; the right testis, epididymides, and vas deferens were normal. Scrotal Doppler ultrasound showed both testes of normal size and contour, bilateral epididymal cysts (largest 0.67 ? 0.46 cm), a 1.09 ? 0.79 cm well-circumscribed hypoechoic lesion in the left testis with internal blood flow, and a small left hydrocele. Laboratory studies revealed a serum CA19-9 level of 57.5 U/mL (normal <27 U/mL); alpha-fetoprotein, human chorionic gonadotropin, and other tumor markers were within normal limits.",Mixed sex cord-stromal tumor "A 7-year-old girl presented with a 6-month history of continuous, non-positional headache, followed by blurred vision for 4 months, postural imbalance for 3 months, and complete loss of vision for the past month. She had no seizures, vomiting, or weight loss. On examination, she was alert but had no light perception in either eye; funduscopic examination revealed bilateral optic atrophy. She had bilateral cranial-nerve III, IV, and VI palsies. Her weight was 19 kg and height 108 cm (normal BMI-for-age; height-for-age indicates stunting). Laboratory studies showed mild leukocytosis (10 230 cells/mm^3). CSF analysis demonstrated elevated glucose (91 mmol/L) and protein (55 mmol/L) levels. Head CT with contrast showed a well-circumscribed isodense mass measuring 3.6 ? 4.6 ? 4.4 cm arising from the right cerebellum, with an inner hypodense component and regular rim enhancement, causing compression of the fourth ventricle and right cerebellar hemisphere, obstructive hydrocephalus, and transependymal edema.",Pilocyticastrocytoma "An 87-year-old Cantonese-speaking man with Alzheimer�s dementia, hypertension, stroke, hyperlipidaemia, gout, peptic ulcer, and chronic kidney disease presented with one week of increasing left leg pain and weakness, impaired mobility, and a single episode of urinary incontinence. He also reported anorexia and a 12% body-weight loss over six months. | |
| On examination, his blood pressure was 88/45 mmHg (responsive to IV fluids), heart rate 96/min, temperature 36.4 �C, and oxygen saturation 95% on room air. He weighed 51 kg (BMI 19 kg/m2). Cardiac and chest examinations were unremarkable. Abdominal examination was normal. Neurologic examination showed 4/5 strength in left hip and knee flexors and extensors; the rest of the exam was normal. | |
| Initial laboratory results demonstrated elevated inflammatory markers (CRP 76 mg/L, WCC 11.9 ? 10^9/L, neutrophils 8.5 ? 10^9/L) and pre-renal acute-on-chronic kidney injury. | |
| An initial differential of cauda equina syndrome or epidural abscess prompted an urgent MRI of the lumbar spine, which showed mild foraminal narrowing at L5�S1 but no central canal stenosis or abscess. He was admitted for possible sepsis; chest X-ray, atypical pneumonia serology, and urine microscopy and culture were all unremarkable. A plain X-ray of the left hip showed no fracture. | |
| Despite analgesia, his left hip pain worsened, strength declined to 2/5 at the hip and 3/5 at the knee, and CRP and ESR continued to rise. A left hip ultrasound revealed a small anterior joint effusion. Normal tumour markers, MRI of the hip, and an isotope bone scan argued against malignancy. Attempts at hip aspiration were unsuccessful. Colchicine was started for presumed crystal arthropathy and atorvastatin was discontinued for possible myopathy, but creatine kinase was normal, and symptoms persisted. | |
| An MRI of the hips and pelvis then demonstrated bilateral iliacus and iliopsoas muscle oedema with enhancement and a left-sided insertional tendinopathy, with no evidence of trochanteric bursitis.",Polymyalgia rheumatica "A 64-year-old white man was admitted in March 2016 with acute-onset abdominal pain and anemia. He had been on therapeutic anticoagulation for paroxysmal �pre-shimmering.� His history included two hypervascular liver lesions in segment IV, first noted in August 2015; biopsies at that time showed histologically proven adenoma without malignancy. On presentation, he was hemodynamically stable but had a hemoglobin level of 4.4 mmol/L. He reported no weight loss, fever, or constitutional symptoms. Laboratory studies showed ?-fetoprotein, carcinoembryonic antigen, and carbohydrate antigen 19-9 levels within normal ranges; serum human chorionic gonadotropin was not measured. Abdominal ultrasound revealed subcapsular hepatic bleeding. Contrast-enhanced CT confirmed active bleeding from one of the two hypervascular lesions in segment IV. After angiographic embolization and conservative management, bleeding resolved. In April 2016, follow-up CT showed persistent hypervascular lesions without typical features of hepatocellular carcinoma. Additional MRI demonstrated hypervascular lesions with central necrosis. Because of suspicion for an atypical hepatocellular carcinoma, an elective surgical resection was planned.",Choriocarcinoma "An 18-month-old girl was brought for evaluation of a swelling in her left medial thigh. Over the past six months, the mass had enlarged gradually and was painless, with no history of trauma or infection. On examination, there was a firm, nonpulsatile mass measuring approximately 10 cm, fixed to underlying tissues but mobile relative to the overlying skin. There were no signs of inflammation, neurovascular impairment, or inguinal lymphadenopathy. | |
| Laboratory tests were unremarkable. A CT scan of the thigh showed a well-defined, lobulated, hypodense mass in the left anteromedial compartment of the proximal thigh, extending toward the inguinal area. The lesion exhibited internal septations and a density similar to subcutaneous fat, displacing the common and superficial femoral vessels anterolaterally without signs of invasion; it abutted the proximal femoral bone but did not erode it. | |
| An MRI confirmed a fatty-appearing, well-circumscribed mass with internal septations and no encasement of neurovascular structures.",Lipoblastoma "A 61-year-old man presented with gross hematuria and intermittent right pelvic pain. His medical history included hypertension, psoriasis, treated pulmonary tuberculosis, and a 60�pack-year smoking history. Urinalysis revealed microscopic hematuria; biochemical tests were normal. Renal ultrasound and cystoscopy showed no abnormalities. Intravenous urography demonstrated a tubular filling defect with partial obstruction of the right mid ureter. Retrograde ureteropyelography confirmed a 5 cm long tubular mass in the mid ureter proximal to the iliac vessels. Flexible ureteroscopy revealed a pedunculated ureteral tumor with a vulnerable surface. Urine cytology and endoscopic biopsy of the lesion and renal pelvis were negative for malignancy. A staging CT scan showed slight dilatation of the right renal pelvis and subtle thickening of the right ureter without evidence of metastasis or lymphadenopathy.",Fibroepithelial polyp "A 60-year-old man with a history of heavy cigarette smoking, emphysema, hypertension, and prostate cancer in remission presented with a 4-hour history of acute right lower-quadrant abdominal pain. On admission, he was febrile (38.5�C), hypotensive (systolic blood pressure 90 mmHg), and tachycardic (heart rate 110/min); examination revealed peritonism in the right lower quadrant. Contrast-enhanced CT of the abdomen showed a perforated appendix with a 51?31?26 mm collection and surrounding fat stranding, innumerable hepatic nodules, mural thickening of the cecum and sigmoid colon, and marked mesenteric, para-aortic, and portocaval lymphadenopathy; there was also pulmonary consolidation and collapse in the right lower lobe. The patient underwent exploratory laparotomy, which revealed a perforated appendix with four-quadrant purulent contamination and a thickened, woody sigmoid colon; a subtotal colectomy with end ileostomy was performed. Postoperatively, he remained ventilated. On day 2, CT of the chest for staging demonstrated bulky multi-station mediastinal lymphadenopathy contiguous with soft tissue thickening enveloping the right lower and middle lobe bronchi. An extubation attempt on day 3 failed, and the patient died on day 6 after withdrawal of care.",small cell lung carcinoma "A 73-year-old man was treated for pneumonia when routine chest imaging revealed an incidental mass in the right posterior mediastinum. He had no compressive symptoms or systemic complaints. Physical examination was unremarkable. Laboratory studies showed hematocrit 25.7% (normal 38�52%), hemoglobin 12.3 g/dL (normal 13�18 g/dL), red-cell count 3.84 ? 10^6/mm^3 (normal 4.0�5.5 ? 10^6/mm^3), platelet count 88,000/mm^3 (normal 160,000�410,000/mm^3), and white-cell count 7000/mm^3 (normal 3800�8500/mm^3) with 58.3% neutrophils, 9.0% lymphocytes, and 25% eosinophils (normal 0�7%). A bone marrow smear revealed dysplastic megakaryocytes and erythrocytes without an increased number of blast cells, consistent with refractory cytopenia with multilineage dysplasia. Contrast-enhanced CT of the chest showed a 38-mm oval, well-encapsulated mass in the posterior mediastinum. On MRI, the lesion had moderate signal intensity on both T1-weighted and T2-weighted images. Because the radiographic findings were not typical for neurogenic tumors, the mass was surgically removed.",myelolipoma "A 45-year-old man presented with recent-onset dry cough and exertional dyspnea. He had no significant past medical history. Initial contrast-enhanced CT of the chest revealed a 12 cm mass in the anterior superior mediastinum and multiple bilateral pulmonary nodules suggestive of metastatic disease. A few weeks later, he developed neck edema, distended neck veins, and facial plethora. Repeat CT confirmed invasion of the superior vena cava above the azygos vein and thrombus extending into the left brachiocephalic trunk. He was treated with heparin and high-dose corticosteroids, with rapid symptomatic relief; stenting was deferred. Video-assisted thoracoscopy yielded a wedge resection of a pulmonary lesion and biopsy of the mediastinal mass. Histopathology showed a multinodular proliferation of small, round, monomorphic cells with clear cytoplasm. Immunohistochemistry demonstrated diffuse strong WT1 positivity and moderate, patchy CD99 positivity.",CIC-rearranged sarcoma "A ten-month-old Hispanic girl presented for evaluation of facial asymmetry noted since birth. The mother reported that when the child smiles or cries, the right lower lip deviates inward, whereas the rest of facial movement is symmetric. Pregnancy was uncomplicated, and the patient was born full term. Developmental milestones are appropriate for age. On examination, her face is symmetric at rest. When she smiles, the right lower lip deviates inward; frowning, forehead wrinkling, eye closure, and nasolabial fold depth are symmetric on both sides. A neurodevelopmental examination is normal. Magnetic resonance imaging of the temporal bones and internal auditory canals is normal, echocardiography shows no cardiac anomalies, and an auditory brainstem response test reveals normal hearing pathways.",congenital unilateral hypoplasia of depressor anguli oris "A 14-year-old girl presented with 6 months of discomfort at the tip of the left middle finger. She had noted that the finger was larger than the others since birth and that it grew progressively. Three months before presentation, she developed tingling at the fingertip and limited flexion of the proximal and distal interphalangeal joints. There was no history of trauma, fever, weight loss, or appetite change. On examination, the middle finger was enlarged but the overlying skin was normal. There was tenderness throughout the enlargement, the temperature was normal, and sensation was decreased distally. Resistance to flexion prevented full finger flexion. Laboratory studies were unremarkable. A CT scan of the hand showed overgrowth of the proximal, middle, and distal phalanges plus surrounding soft tissue; normal bone trabeculation; and no abnormal vascular structures, suggesting a lipomatous process.",macrodystrophia lipomatosa "A 39-year-old man presented with a one-week history of epigastric pain and hematemesis. He had no significant medical or surgical history, took no medications, and had no allergies. He was a smoker and did not drink alcohol. On examination, vital signs were stable, the abdomen was soft without tenderness, and a rectal examination revealed no melena. Laboratory studies showed a hemoglobin level of 6.3 g/dL; after transfusion, it rose to 10 g/dL. Upper gastrointestinal endoscopy revealed a submucosal lesion in the gastric antrum with ulceration of the overlying mucosa. Biopsy showed no malignant features. Contrast-enhanced abdominal CT revealed a well-defined, heterogeneous, pre-pyloric mass measuring 6?5 cm with fat attenuation in the antropyloric region.",Gastric lipoma "A 52-year-old man with no prior medical history initially presented with an eight-month history of diffuse abdominal pain, obstipation, and an 8-kg weight loss. Three weeks before admission he had a chronic cough; chest radiograph and spirometry were normal, and inhaler therapy relieved his symptoms. On admission, his C-reactive protein was elevated at 96.1 mg/L, white blood cell count was 13.85 ? 10^3/�L, and hemoglobin was 13.7 g/dL. He received empiric cefuroxime and metronidazole. Colonoscopy was unremarkable, and abdominal CT showed pathologically enlarged retroperitoneal lymph nodes and ascites. | |
| While under evaluation for suspected lymphoma, he developed sudden?onset dyspnoea. Arterial blood gases showed pH 7.48, pO2 56 mmHg, pCO2 25 mmHg. ECG revealed new T-wave inversions in leads V1�V3. Transthoracic echocardiography demonstrated a markedly dilated right ventricle, reduced RV function (TAPSE 1.5 cm), and estimated systolic pulmonary artery pressure of 70 mmHg. | |
| A CT pulmonary angiogram showed no evidence of pulmonary arterial embolism or deep vein thrombosis but did show small bilateral ground-glass opacities and pleural effusions. Laboratory studies revealed an NT-pro-BNP of 17 126 pg/mL (baseline 558 pg/mL), D-dimer 11.6 mg/L, and a stable, modest elevation of high?sensitivity troponin I at 123.2 pg/mL. His oxygen requirement increased to 8 L/min, and a ventilation/perfusion scan demonstrated diffuse, subtle perfusion defects �compatible with mild bronchial obstruction rather than PAE.�",pulmonary tumour microembolism "A 65-year-old woman with a history of distal pancreatectomy for pancreatic cancer and ongoing TS-1 therapy presented with fever. Two months earlier, liver metastasis was diagnosed, and she began FOLFIRINOX chemotherapy 15 days before admission, with pegfilgrastim administered 12 days before admission to prevent myelosuppression. Four days before admission to general surgery, she developed fever (37�C) and elevated C-reactive protein (11.8 mg/dL) and was admitted. Contrast-enhanced CT showed soft-tissue thickening around the aortic arch without dissection. | |
| On transfer to rheumatology, she reported chest pain over the aortic arch. Vitals were blood pressure 120/71 mmHg, pulse 98/min, temperature 39.1�C, and oxygen saturation 98% on room air. Cardiovascular and pulmonary exams were normal, and there were no skin lesions. Laboratory studies showed an erythrocyte sedimentation rate of 94 mm/h, C-reactive protein of 7.45 mg/dL, macrocytic anemia, hypoalbuminemia, mildly elevated rheumatoid factor (20.8 IU/mL), negative other autoantibodies, CA19-9 of 92.0 U/mL, and negative blood cultures and serologies for syphilis and Chlamydia. | |
| Contrast-enhanced CT confirmed weakly enhancing soft-tissue thickening of the aortic arch wall, and large-vessel MRI demonstrated wall enhancement consistent with aortitis. She was treated empirically with minocycline, after which fever and inflammation resolved within one week, and CT showed regression of wall thickening. She continued FOLFIRINOX with pegfilgrastim, with occasional transient fevers and CRP elevations that resolved spontaneously. | |
| Four months later, during her seventh cycle of chemotherapy, she developed a high fever (39�C) and a CRP of 13.68 mg/dL. Contrast-enhanced CT revealed soft-tissue thickening around the descending aorta without involvement of the aortic arch, and she was referred again for evaluation of aortitis.",G-CSF-induced aortitis "A 30-year-old woman presented with 2 months of worsening dyspnea, dry cough, fatigue, and a 20-kg weight loss over 5 months. She denied fever, bowel changes, and relevant medical or malignancy history and had a negative SARS-CoV-2 PCR test. Vital signs were normal except for mild tachycardia (119 bpm) and oxygen saturation of 93%. Examination revealed decreased right lung breath sounds and minimal ascites. Labs showed hemoglobin 8.1 g/dL, elevated erythrocyte sedimentation rate (92 mm/h), albumin 3.3 g/dL, AST 32 U/L, and CA-125 121 U/mL (reference <35). Chest radiograph demonstrated bilateral pleural effusions, right infiltrate, and cardiomegaly from pericardial effusion. Noncontrast chest CT confirmed bilateral pleural and pericardial effusions, mediastinal lymphadenopathy, and lytic lesions in the sternum, right humerus, and thoracic vertebrae. She was treated for pneumonia, and dyspnea improved. On hospital day 5, PET-CT showed FDG-avid thickening of bilateral adnexa suspicious for primary ovarian malignancy, hypermetabolic osteolytic lesions in bone, hypermetabolic lymph nodes, pericardium, and pleura, and non-FDG-avid omental and colonic wall thickening. On hospital day 7, gynecologic ultrasound showed normal-sized uterus and ovaries with no masses or cysts, in contrast to the PET-CT findings.",abdominal tuberculosis "A 74-year-old man with a history of metastatic prostate cancer and a known left upper lobe lung mass presented with four weeks of progressive vertigo, described as the sensation that �the floor was wobbling� and �the room was swaying,� leading to difficulty ambulating. A few days before admission, he developed severe bifrontal throbbing headaches with nausea and vomiting. Two days prior, he was evaluated at an outside emergency department, tested positive for adenovirus, and was discharged after supportive treatment without symptom relief. | |
| His oncology history included stage III prostate adenocarcinoma treated with prostatectomy and radiation in 2013, followed by detection of bilateral lung nodules and sclerotic bone lesions in 2016, and a 2020 biopsy of a left upper lobe lesion confirming mismatch repair deficient, androgen receptor�positive metastatic prostate cancer treated with enzalutamide, then abiraterone acetate and prednisone, and palliative radiation. | |
| On presentation, vital signs were: temperature 37�C, heart rate 90 beats/min, blood pressure 164/81 mm Hg, and oxygen saturation 93% on room air. Neurologic examination revealed no focal motor or sensory deficits; intact coordination on dysdiadochokinesia, finger-to-nose, and heel-to-shin testing; an intact gait despite dizziness; and a positive right-sided Dix�Hallpike maneuver with horizontal nystagmus. | |
| Noncontrast head CT showed a 3 cm left cerebellar hemispheric mass with surrounding vasogenic edema causing mild partial effacement of the fourth ventricle and left quadrigeminal cistern. The patient received dexamethasone. MRI of the brain demonstrated a cystic enhancing lesion in the left cerebellar hemisphere with mass effect; no other intra-axial lesions were identified. Cerebral angiography revealed no abnormal hyperemia at the site of the lesion. | |
| A hemangioblastoma was considered the leading diagnosis; other considerations included metastases and infarction.",metastatic prostate carcinoma "A 21-year-old woman with autism spectrum disorder (on risperidone) and intellectual disability was brought to the hospital after a witnessed collapse. She had no prior history of syncope, cardiac arrest, or known cardiovascular disease, and her family denied any illicit drug or alcohol use. While at a noisy auto mechanic shop, she became pale and lost consciousness; bystander ECG showed ventricular fibrillation. Return of spontaneous circulation was achieved after two defibrillations. On arrival, her blood pressure was 93/70 mmHg, pulse 86 bpm, and oxygen saturation 100% (bag�valve�mask). An intravenous amiodarone infusion (1 mg/min) and oral amiodarone 400 mg were administered. On examination she was comatose (GCS 3), with agonal respirations; cardiovascular examination was unremarkable. In the intensive care unit, her differential diagnosis included channelopathies, hypertrophic cardiomyopathy, and metabolic abnormalities. Laboratory tests showed normal chemistry panel and electrolytes. Initial electrocardiogram revealed sinus rhythm with interpolated premature ventricular complexes and a QTc of 380 ms, without any evidence of infarction, pre-excitation, or Brugada pattern. Transthoracic echocardiography demonstrated an ejection fraction of 45�50%, normal wall thickness, and no valvular abnormalities.",Catecholaminergic polymorphic ventricular tachycardia "A 59-year-old man was referred for evaluation of a crusty lesion in the right fronto-orbital region present for several months. He had no significant past medical history. On examination, there was an irregularly shaped 5 ? 3 cm plaque with multiple superficial crusts. Laboratory studies were unremarkable. | |
| An excisional biopsy of the lesion showed lobules and detached aggregates of eosinophilic keratinocytes with pleomorphic nuclei and prominent nucleoli infiltrating the reticular dermis; there was no clear evidence of basaloid nests, and the diagnosis rendered was invasive cutaneous squamous cell carcinoma. | |
| On April 24, he began treatment with cemiplimab 350 mg every 3 weeks. Before therapy, ^18F-FDG PET/CT demonstrated a focal area of uptake in the supraorbital lesion (SUVmax 6.9; metabolic tumor volume, 2 cc). After five cycles, the plaque had regressed markedly, but several discrete papular lesions remained. Dermoscopic evaluation of these papules revealed features typical of basal cell carcinoma. A follow-up PET/CT at 12 weeks showed decreased uptake in the original lesion (SUVmax 4.8; metabolic tumor volume, 0.5 cc), consistent with partial metabolic response.",BasosquamousCarcinoma "A 65-year-old man with benign prostatic hyperplasia presented for urologic evaluation. His prostate-specific antigen level was 0.796 ng/mL. Uroflowmetry revealed reduced urine flow, prolonged micturition time, and obstructive findings. He was started on oral Alfuzosin 10 mg once daily. On day 9 of therapy, he reported loss of appetite and malaise, followed by generalized pruritus, dark urine, and jaundice. He denied use of aspirin, acetaminophen, or herbal medicines and had no history of liver disease. On examination, he was jaundiced but had no stigmata of chronic liver disease. Laboratory studies showed leukocyte count 5.8 K/?L, AST 175 U/L (0�40), ALT 402 U/L (0�55), alkaline phosphatase 235 U/L (15�250), ?-glutamyl transferase 327 U/L (8�61), total bilirubin 7.6 mg/dL (0.2�1.2), and direct bilirubin 5.8 mg/dL (0�0.25). Abdominal ultrasonography showed normal liver, gallbladder, common bile duct, and intrahepatic bile ducts. Serologic tests for HBsAg, anti-HBc IgM, anti-HCV, anti-HAV IgM, anti-HEV, HEV RNA, and HCV RNA were negative. Autoimmune markers (ANA, AMA, ASMA, LKM-1) were negative. Metabolic evaluations�including transferrin saturation, ferritin, alpha-1 antitrypsin, ceruloplasmin, 24-hour urinary copper, and ophthalmologic exam for Kayser�Fleischer rings�were normal. Magnetic resonance cholangiopancreatography demonstrated a normal biliary anatomy.",drug-induced liver injury "A 52-year-old woman with a history of long-standing diplopia was evaluated in clinic for persistent vertical misalignment. In 2005, MRI of the orbits revealed an anomalous band in the right orbit, which was surgically excised without improvement in motility; her diplopia remained stable in primary gaze. On examination in 2023, she was orthotropic in primary position but had an elevation deficit of the right eye. MRI of the orbits with and without gadolinium was obtained. The globes were unremarkable with no measured proptosis. The retroocular fat, optic nerves and sheaths, optic chiasm, and brain parenchyma appeared normal. A right orbital linear soft-tissue lesion was noted medial to the medial rectus muscle, parallel to it, with enhancement and signal-intensity characteristics identical to those of extraocular muscle, and it was unchanged from the previous study.",Accessory extraocular muscle "A 35-year-old woman presented with an 8-month history of radicular pain radiating from her lower back down the left leg, with occasional tingling. The pain progressively worsened and was particularly severe by August. She denied any weakness, autonomic symptoms, history of trauma, or injury. On examination, she had mild hypesthesia in the left L5�S1 dermatome but normal muscle strength, normal abduction and adduction, and negative Las�gue, Kernig, Bragard, and Sicard signs. Electromyography showed neuropathic irritation of the left L4, L5, S1, and S2 roots, most severe at L5, with no denervation. Lumbosacral gadolinium-enhanced MRI revealed a solitary, completely cystic mass in the left L5�S1 foraminal zone extending along the course of the sciatic nerve into the left ischial groove, measuring approximately 13.9 cm in length and 1.9 cm in maximal diameter. The lesion was hypointense on T1-weighted images, hyperintense on T2-weighted images, and demonstrated peripheral rim enhancement, causing severe foraminal stenosis without attachment to pelvic organs. MR neurography confirmed that the mass arose from the sciatic nerve at the left ischial groove.",schwannoma "A 23-year-old woman with an 11-year history of type 1 diabetes mellitus (mean HbA1c 12.1% over 2 years) presented with 14 days of sharp, intermittent right-sided abdominal pain that worsened with eating and was associated with nausea. She had multiple prior admissions for diabetic ketoacidosis. On examination, her BMI was 17.5, heart rate 117 bpm, and she was tender in the right upper and lower quadrants without guarding or rebound; the liver was palpable 3 inches below the right costal margin. Laboratory evaluation showed: blood glucose 344 mg/dL, anion gap 17, bicarbonate 18 mEq/L, venous pH 7.31, serum ketones <1:4 dilution, trace urine ketones; after 2 L IV fluids, glucose fell to 76 mg/dL and her usual insulin regimen was resumed. AST 511 U/L, ALT 366 U/L, ALP 304 U/L, lactic acid 8.0 mg/dL, total bilirubin 0.4 mg/dL, albumin 4.0 g/dL, INR 0.9, platelets 248?10^3/�L, HbA1c 11.5%; amylase and lipase were normal. Contrast CT of the abdomen showed liver enlargement to 26 cm with mass effect on adjacent structures; Doppler ultrasound excluded hepatic vein thrombosis. She was on no hepatotoxic medications. Infectious workup (EBV, CMV, hepatitis A, B, C), iron studies (ferritin, iron, saturation), ceruloplasmin, alpha-fetoprotein, and thyroid function were within normal limits. Celiac serologies (tissue transglutaminase, endomysial antibody) were negative. Autoimmune markers (ANA, anti�smooth muscle, antimitochondrial, liver/kidney microsome) were negative. Transthoracic echocardiogram showed normal biventricular function with an ejection fraction of 55�60%.",Glycogenic hepatopathy "A 59-year-old woman presented with a lump in the lower outer quadrant of her left breast. Six years earlier, she had undergone breast-conserving surgery with endocrine therapy and radiation (50 Gy in 25 fractions) to the left breast for an upper inner quadrant carcinoma. On examination, there was a 20 mm firm mass fixed to the pectoralis major muscle; the overlying skin was uninvolved and there were no palpable axillary lymph nodes. | |
| Mammography showed a focal asymmetrical density in the retromammary space. Ultrasonography revealed a lobulated, well-defined mass measuring 17.5 ? 16.4 ? 10.6 mm with relatively hypoechoic, heterogeneous internal echoes. A core-needle biopsy of the lesion suggested only atrophic mammary glands. On three-month follow-up, the lesion had increased in size.",Leiomyosarcoma "A 14-year-old girl presented with 2 months of progressive proximal muscle weakness. She initially noted difficulty combing her hair and rising from a chair; over weeks she became wheelchair-bound. She also reported morning stiffness of both small hand joints lasting about 30 minutes, dysphagia for solids and liquids, and poor appetite, without fever or weight loss. | |
| Her medical history was notable for thyroiditis in 2015 that resolved without long-term therapy. Family history included a younger sister with Prader�Willi syndrome. She was up to date on vaccinations. | |
| On examination, vital signs were normal. Neurologic testing showed symmetric muscle strength of 4/5 in the upper limbs and 3/5 in the lower limbs, with brisk reflexes more pronounced on the left. She could not stand from the wheelchair unaided. In the left hand, she was unable to make a fist or tuck the fingers; there was tenderness at the fourth and fifth proximal interphalangeal and metacarpophalangeal joints bilaterally. The remainder of the physical examination was unremarkable. | |
| Laboratory studies revealed leukopenia (WBC 2.96???10^3/�L), microcytic anemia (hemoglobin 10.4?g/dL), elevated C-reactive protein (18.8?mg/L) and erythrocyte sedimentation rate (109.2?mm/hr), and normal creatine kinase (39?U/L). Thyroid function tests showed suppressed TSH (0.017?�IU/mL), elevated free T4 (20.9?pmol/L), normal free T3 (4.53?pmol/L), and markedly elevated anti-thyroglobulin antibodies (3410?IU/mL). Antinuclear antibody titer was 27 (reference <20); rheumatoid factor, anti-CCP, and ANCA were negative. Viral serologies, renal and liver tests, and other hormonal assays were normal. | |
| Hyperkalemic paralysis was ruled out. Thyroid ultrasound demonstrated a multinodular goiter consistent with thyroiditis. MRI of the brain and lumbosacral spine was normal; cervical spine MRI showed a small C6�C7 disc herniation. Incidentally, the lumbosacral spine MRI revealed bilateral sacroiliitis. Dedicated MRI of the sacroiliac joints confirmed bilateral sacroiliitis; HLA-B27 was negative. MRI of the hips and pelvis showed bilateral thigh intramuscular edema with enhancement. Although myositis was suspected, electromyography and repeat creatine kinase were normal.",Macrophage myofasciitis "A 74-year-old man with type 2 diabetes mellitus, hypertension, ischemic stroke, peripheral arterial disease, bilateral nonobstructive renal artery stenosis, chronic right internal carotid occlusion, seizures, and vascular dementia was transferred from a nursing home because of decreased oral intake and dehydration for at least one week. En route, his blood pressure was 94/49 mmHg, and he received 1 L of intravenous normal saline. On arrival, he was somnolent and oriented only to self. His vital signs were: temperature 37.1 �C, blood pressure 101/59 mmHg, heart rate 105 beats per minute, respiratory rate 17 breaths per minute, and oxygen saturation 100% on room air. Examination revealed a sarcopenic-appearing man with dry mucous membranes and no acute distress. | |
| Initial laboratory results were notable for acute renal failure and severe metabolic acidosis: sodium 145 mEq/L, potassium 6.6 mEq/L, blood urea nitrogen 207 mg/dL, creatinine 10.2 mg/dL (baseline 1.1 mg/dL), glucose 185 mg/dL, chloride 106 mEq/L, bicarbonate 8 mEq/L, anion gap 31, venous pH 7.09, and lactate 4.4 mmol/L. A urinary catheter revealed trace ketones on repeat urinalysis. A ?-hydroxybutyrate level was elevated at 31.5 mmol/L. High-sensitivity troponin levels were 213 ng/L at baseline, 223 ng/L at 1 hour, and 193 ng/L at 3 hours; electrocardiogram showed normal sinus rhythm without ST-T changes. | |
| His home medications included insulin glargine 18 units nightly, insulin aspart 5 units before each meal, and empagliflozin started one month earlier.",Euglycemic diabetic ketoacidosis "A 55-year-old woman with a history of hypertension presented with two months of progressive dyspnea and bilateral lower-extremity edema. She denied chest pain, abdominal pain, gastrointestinal symptoms, fevers, or weight loss. She was a lifetime nonsmoker and drank alcohol socially (<2 drinks/month). Medications included losartan 50 mg daily. | |
| On admission, liver-function tests showed an alkaline phosphatase of >500 U/L, aspartate aminotransferase 70 U/L, alanine aminotransferase 65 U/L, total bilirubin 1.0 mg/dL, and an international normalized ratio of 1.16. A CT scan of the chest, abdomen, and pelvis with contrast revealed a uterine mass. Endometrial biopsy confirmed endometrial carcinoma. Workup for liver disease included a negative hepatitis panel, normal iron studies, negative smooth-muscle antibody, and an unremarkable right-upper-quadrant ultrasound. | |
| During outpatient evaluation, her alkaline phosphatase rose to 714 U/L, with aspartate aminotransferase 120 U/L, alanine aminotransferase 94 U/L, total bilirubin 1.5 mg/dL (direct 0.8 mg/dL), and international normalized ratio 1.2. Additional testing showed negative liver-kidney microsomal antibody, antimitochondrial antibody, and anti�smooth-muscle antibody; normal ceruloplasmin and alpha-1 antitrypsin levels; and an elevated antinuclear antibody titer of 1:160. A core liver biopsy demonstrated marked ductal reaction and mild focal cholestasis. | |
| Staging positron-emission tomography showed uptake in the primary uterine tumor and abdominopelvic lymph nodes, with no lesions in the liver or gallbladder. Two months after presentation, she underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy and lymph node dissection for FIGO stage III C2 endometrial adenocarcinoma. | |
| On follow-up, liver chemistries remained abnormal, and MRI/MRCP was recommended but deferred because of postoperative acute kidney injury. Two weeks after surgery, she was readmitted with alkaline phosphatase 2188 U/L, aspartate aminotransferase 338 U/L, alanine aminotransferase 113 U/L, total bilirubin 4.5 mg/dL (direct 3.6 mg/dL), and creatinine 1.8 mg/dL. She reported new jaundice, bilateral hand pain, distal skin tightening, and �blue fingers.� Examination revealed scleral icterus, diffuse jaundice, sclerodactyly, and ulcerations at the digital pits. | |
| Serologic studies were positive for anti�centromere and anti�RNA polymerase II antibodies, and paraneoplastic scleroderma was diagnosed. Given concern for autoimmune liver disease, she underwent repeat liver biopsy and was started empirically on prednisone 40 mg daily, but her liver tests did not improve. Endoscopic retrograde cholangiopancreatography was performed and showed no stricture or obstruction, with a normal cholangiogram.",Vanishing bile duct syndrome "A 62-year-old woman presented with a one-month history of burning sensation and discomfort in her left breast without fever or systemic symptoms. She had hypertension and a remote history of hemorrhoidectomy, dilation and curettage, colonoscopy, and gastroscopy; she was a heavy smoker. On examination, there was a 3 ? 3 cm palpable mass in the upper quadrant of the left breast without overlying skin changes. No axillary or supraclavicular lymphadenopathy was noted. Routine blood tests, chest radiograph, and ECG were unremarkable. Breast MRI revealed an ill-defined, deep retroareolar spiculated lesion measuring 3 ? 1.5 cm with an early enhancement peak and associated architectural distortion; no axillary lymphadenopathy or skin thickening was identified (BIRADS IV). An excisional biopsy showed breast tissue containing cohesive nests of neoplastic epithelial cells within a dense lymphoid infiltrate. Immunohistochemical staining demonstrated that the epithelial cells were positive for cytokeratin AE1/E3 and negative for estrogen receptor, progesterone receptor, and HER2/neu; the background lymphocytes stained positive for CD3 and CD20.",Lymphoepithelioma-like carcinoma of the breast "A 58-year-old man presented with abdominal pain that began around the umbilicus 2 days earlier and migrated to the right lower quadrant. He had no prior abdominal surgeries or systemic disease. He denied anorexia, nausea, vomiting, dizziness, weight loss, night sweats, diarrhea, or constipation. On examination, he was afebrile; heart rate was 86 bpm, and blood pressure was 130/95 mm?Hg. Abdominal examination showed voluntary guarding in the right lower quadrant and minimal tenderness elsewhere. Laboratory tests revealed a white-cell count of 15,600/mL, hemoglobin of 14.2?g/dL, and platelet count of 126,000/mL. Plain abdominal X-rays demonstrated several air�fluid levels without free air under the diaphragm. Ultrasound assessment was interpreted as compatible with plastron appendicitis. Computed tomography of the abdomen revealed a linear lesion within the intestinal lumen in the right lower quadrant, causing partial luminal obliteration and edema on the anterolateral aspect of the cecum.",Small intestinal perforation "A 67-year-old woman with a 31-year history of recurrent depressive disorder presented with depressed mood, anhedonia, nervousness, fatigue, decreased appetite, and poor sleep beginning 5 months after COVID-19. She had two severe episodes responsive to escitalopram (up to 20 mg/d) and duloxetine (up to 60 mg/d), and intolerance to venlafaxine, bupropion, and trazodone. Her mother had mania; she denied iron deficiency anemia, hypothyroidism, or substance abuse. Physical and neurologic examinations and routine laboratory tests were unremarkable. On admission, she was receiving escitalopram 10 mg/d, duloxetine 80 mg/d, and clonazepam 1.5 mg/d. On hospital day 3, she reported new deep itching and creeping sensations in her bilateral shoulders and arms, worse at rest, partially relieved by movement, and predominantly occurring in the evening, causing night-time sleep disturbance. Escitalopram was discontinued and duloxetine increased to 100 mg/d while clonazepam was reduced. One week later, the paraesthesias persisted despite reducing duloxetine to 90 mg/d and clonazepam to 0.5 mg/d.",Restless arms syndrome "A 65-year-old woman presented with right dorsal pain. Laboratory studies showed total bilirubin 1.3 mg/dL, alkaline phosphatase 452 IU/L, and ?-glutamyl transferase 167 IU/L. The indocyanine green plasma disappearance rate was 0.103, and the 15-minute retention rate was 23.9%, indicating depressed liver function. Tests for hepatitis B and C viral markers were negative. Serum levels of ?-fetoprotein, PIVKA-II, CEA, and CA19-9 were within normal limits; DUPAN-2 was 200 U/mL, CA125 was 321.8 U/mL, and neuron-specific enolase was 29.2 ng/mL. | |
| Abdominal CT revealed a well-defined, low-density, heterogeneous, multilocular cystic tumor with septa replacing the right hepatic lobe and medial segment of the left lobe, measuring 16 cm in diameter, with an enhancing solid compartment and a nonenhancing cystic compartment, compressing the umbilical portion of the portal vein, the right portal vein, and the left hepatic vein. MRI showed mixed high and low signal intensity: cysts were low on T1-weighted images and high on T2-weighted images, and areas of high T1 and low T2 signal suggested intratumoral hemorrhage. Abdominal ultrasound demonstrated a honeycomb-like tumor with solid components. PET�CT showed FDG uptake in the solid components of the cyst. From these imaging findings, the preoperative diagnosis of mucinous cystadenocarcinoma or sarcoma of the liver was made.",undifferentiated embryonal sarcoma of the liver "A 62-year-old woman presented with what appeared to be a left-sided gluteal abscess. On examination, a firm nodule was palpated in the gluteal region. Her white-cell count was 9500 per ?L, and a random serum glucose level was 140 mg/dL. The lesion was surgically drained and excised, and culture of the drained fluid yielded Escherichia coli susceptible to amikacin and cefepime; therapy with cefepime was initiated. Gross examination of the specimen revealed a 6.5?2.5?1.2 cm piece of fibro-fatty tissue covered by skin and containing a relatively circumscribed, soft-to-firm yellowish nodule measuring 3.5?2 cm, with a least surgical margin of 0.2 cm. Microscopic examination showed a downward proliferation attached to the epidermis and extending into the deep dermis, composed of cords and nests of small uniform keratinocytes sharply delimited from the adjacent epidermis; duct-like structures and occasional islands of squamous epithelium were present, along with dermal reactive vessels and mixed inflammatory cells with neutrophil collections. The reporting pathologist suggested a diagnosis of poroma versus a low-grade malignant tumor; subsequent blinded consultation by three additional pathologists confirmed the diagnosis of eccrine poroma with clear margins.",eccrine poroma "A 38-year-old woman presented for an annual examination with a 3-year history of painless swelling of the left labia majora that began after her last cesarean delivery. She is G2P2 with a surgical history significant for two cesarean deliveries, tubal ligation, appendectomy, and benign breast tumor excision. She has no personal or family history of gynecologic cancer or sexually transmitted infections. She noted numbness over the swollen area and progressive dyspareunia but denied discharge, pruritus, pain on palpation, or urinary symptoms. | |
| On gynecologic examination, the left labia majora was enlarged, containing an elongated, soft, nonmobile, nontender, sausage-like mass measuring approximately 12 ? 6 ? 4 cm extending from the mons pubis to the anal verge along the left labial fold. There were no overlying skin changes or drainage. The remainder of the physical examination was unremarkable. | |
| Abdominal and pelvic CT with oral and intravenous contrast demonstrated left labial edema without ascites or inguinal or pelvic lymphadenopathy. The lesion was confined to the vulva and did not extend beyond the pelvic diaphragm; however, a vulvar mass could not be excluded. The differential diagnosis included a labial neoplasm, cyst of the canal of Nuck, and a hernia.",aggressive angiomyxoma "A 70-year-old man with extensive nicotine use and a remote history of laryngeal squamous cell carcinoma (7 years prior) and bladder urothelial carcinoma (10 years prior) underwent dual-chamber pacemaker implantation for sick sinus syndrome 9 months ago. Postoperative checks on days 1, 2, and at 3 months showed normal pacemaker function and a clinically unremarkable pocket. Three weeks before presentation, he tested positive for COVID-19 infection, but his fatigue, dyspnea, and cough persisted and worsened rather than improving. At a routine cardiology visit 9 months after implantation, he reported a new, painless but bothersome swelling over the pacemaker site. On examination, his blood pressure and heart rate were normal, and there were no signs of cardiac decompensation or cachexia. Chest ultrasound revealed a soft tissue mass with increased vascularity surrounding the device. CT imaging confirmed a soft-tissue mass around the pacemaker pocket, and haematoma or infection was excluded.",squamous cell carcinoma "A 36-year-old Asian man presented with a 4-month history of worsening headaches and complete right homonymous hemianopia. Two years earlier, he had a left occipital intracerebral hematoma of unknown cause. On examination, vital signs were normal, and neurologic testing confirmed the visual field defect without other focal deficits. | |
| Noncontrast head CT showed a left occipital intraparenchymal hemorrhage. Contrast-enhanced brain MRI revealed a left tentorial extra-axial enhancing mass with adjacent parenchymal hemorrhage, suggesting a cavernous angioma. The patient underwent a left occipital craniotomy; intraoperatively, the mass was found to invade the falx cerebri and adjacent cortex, limiting resection to subtotal removal. Postoperative CT showed no complications. | |
| Histopathological examination demonstrated spindle cells forming masses with branching ectatic vasculature, focal collagenous regions, and up to 20 mitoses per ten high-power fields. Immunohistochemical studies showed strong immunoreactivity for CD31, CD99, and Fli-1, with scattered S100-positive cells, and negative staining for CD34, EMA, desmin, muscle-specific actin, and Bcl-2.",Angiosarcoma "A 62-year-old man presented with increased frequency of ear infections and recurrent impaction of cerumen. On otoscopic examination, there was significant bilateral narrowing of the external auditory canals, impairing visualization of the tympanic membranes, more pronounced on the right. The patient described previous cerumen removals as so uncomfortable that anesthesia was required. He reported awareness of bony outgrowths in both ear canals for the past 30 years and had declined surgical treatment when first offered. Further history revealed that he was an avid free-diver daily during summer months from early teens to late adulthood without any ear protection; he ceased diving 15 years ago. High-resolution CT of the temporal bones demonstrated bilateral dense, sessile osseous outgrowths arising from the osseous portion of the external auditory canals, causing near-occlusion of the canals with residual luminal diameters of 1�2 mm; no soft tissue densities or bone erosions were observed.",external auditory exostosis "A 36-year-old woman with rheumatic mitral stenosis status post mitral valvotomy and two valve repairs presented with 4 days of progressive dyspnea on exertion, orthopnea, and paroxysmal nocturnal dyspnea. Two weeks earlier she had received streptokinase for suspected prosthetic mitral valve thrombosis. Over the past 3 days she noted fever and bilateral knee pain without photosensitivity, rashes, myalgia, malaise, or lymphadenopathy. Her bowel and bladder habits were unchanged. | |
| On examination: temperature 98.6�F, pulse 70/min, respirations 20/min, blood pressure 100/70 mmHg. No pallor, icterus, cyanosis, edema, or jugular venous distension. Dermatologic, cardiovascular, and respiratory exams were unremarkable. Joint exam showed no swelling, erythema, or warmth. | |
| Laboratory studies revealed hemoglobin 9.65 g/dL, neutrophils 41%, lymphocytes 43%, platelets 4,456,000/�L, prothrombin time 32.8 s, INR 2.5. Blood urea nitrogen, creatinine, sodium, and potassium were within normal limits. The erythrocyte sedimentation rate was elevated and C-reactive protein (late?) was positive. Blood and urine cultures were sterile. Serologic tests for hepatitis B surface antigen, antinuclear antibody, anti�cyclic citrullinated peptide antibody, and lactate dehydrogenase were negative.",Serum sickness "A 32-year-old man presented with a six-year history of a painless swelling in the left supraclavicular region that had gradually enlarged from the size of an almond to that of a lime. He reported no history of trauma, fever, or systemic illness, and no weakness, numbness, or loss of function in the upper limb. On examination, there was a 4.0-cm diameter, round, firm, non-tender mass in the left supraclavicular area that was mobile in the medio-lateral direction. An ultrasound showed a superficial heterogeneous round cystic mass measuring 47 ? 33 mm lateral to the sternocleidomastoid muscle, with well-defined smooth margins and multiple intralesional septa; its lower border lay adjacent to the subclavian artery and its medial border abutted the carotid artery and external jugular vein. The ultrasound was interpreted as a branchial cleft cyst with an atypical location. Fine needle aspiration was performed, and the cystogram findings corroborated this diagnosis. The patient was scheduled for surgical excision of the suspected branchial cleft cyst.",Schwannoma "A 33-year-old man with known HIV/AIDS not on antiretroviral therapy (CD4 count <20 cells/�L), prior intravenous drug use, and active tobacco dependence was brought from his nursing home after abnormal laboratory results. He reported one month of poor appetite, weight loss, and subjective fevers, and several days of diarrhea without abdominal pain, vomiting, cough, or dyspnea. On examination, he was febrile (39.4 �C), hypotensive (91/60 mmHg, improved with IV fluids), tachycardic (130 bpm), and lethargic. Initial labs showed leukocytosis (31 151/�L) and hyponatremia (Na 121 mEq/L). A chest radiograph was clear. Abdominal ultrasound revealed hepatosplenomegaly, ascites, and enlarged peripancreatic lymph nodes. He was admitted to the ICU with presumed sepsis and started on vancomycin, piperacillin�tazobactam, and metronidazole. He then developed acute hypoxic respiratory failure and septic shock requiring intubation; post?intubation chest radiograph showed new bilateral infiltrates. Blood cultures remained negative. Lumbar puncture demonstrated an opening pressure of 35 cm H?O, 1825 RBCs/dL, 1 WBC/dL, glucose 65 mg/dL, and protein 36 mg/dL, and acyclovir was started empirically. Bronchoalveolar lavage was negative for bacterial, viral, fungal, and Pneumocystis jirovecii cultures. Initial sputum smears for acid?fast bacilli were negative.",Tuberculosis "A 28-year-old man with a history of migraine disorder presented with several months of pain and swelling in the right mastoid area, with a recent subjective enlargement of the mass and increased pain. Noncontrast CT of the head demonstrated a 3.0 ? 3.0 ? 1.1 cm hyperostotic lesion of the outer table of the right calvarium without intracranial extension or adjacent soft-tissue mass. Because of the new-onset pain and subjective growth of the lesion, surgical excision was planned, and MRI with and without contrast was obtained. MRI revealed a densely calcified mass measuring 3.6 ? 1.5 ? 3.0 cm involving the inferior squamosal portion of the right temporal bone, with low signal intensity on T1- and T2-weighted images, mild patchy internal enhancement, thickening of the inner table, and no soft-tissue component beyond the bone or dural involvement. A small amount of fluid was noted in the right mastoid air cells, and mucosal thickening was present in the right ethmoid air cells. Laboratory studies, including a complete blood count, basic metabolic panel, thyroid-stimulating hormone, and free T4, were within normal limits.",ParostealOsteosarcoma "A 10-year-old girl presented with a 1-year history of a rapidly enlarging left breast mass. There was no history of pain, trauma, fever, anorexia, or weight loss. She was premenarcheal, and there was no significant family history. On examination, the left breast had a 20 cm ? 20 cm well-circumscribed, firm, non-tender, mobile lump; the right breast was normal. The mass was not fixed to skin or underlying muscle. The overlying skin was tense and shiny with prominent superficial veins. There was no nipple discharge and no axillary lymphadenopathy. Routine hematological and biochemical tests, including ESR, were within normal limits. A chest radiograph was normal. Ultrasonography of the left breast revealed a heterogeneous parenchymal pattern suggestive of fibroadenoma. Fine-needle aspiration cytology of the lump showed pathology suggesting fibroadenoma.",giant juvenile fibroadenoma "A 31-year-old Brazilian woman was referred for evaluation of a diffuse 20 mm radiolucent lesion in the right maxilla associated with teeth 13 and 15 and an overlying painless swelling. She reported prior endodontic treatment of teeth 13 and 15 without regression of the lesion. Teeth 14 and 24 had been extracted previously for orthodontic reasons. Panoramic radiography and CT confirmed a unilocular radiolucency involving the apices of teeth 13 and 15. The initial working diagnosis was an inflammatory periapical cyst. Preoperative laboratory tests were obtained, and the patient underwent excisional biopsy of the lesion under general anesthesia.",central giant cell lesion "A 34?year?old African American man with hemophilia A, HIV?1 infection, and hepatitis C virus infection presented with a 3?month history of intermittent fever, unintentional weight loss, and progressive lip swelling with painful ulcerations. Six months earlier he had resumed antiretroviral therapy, with his CD4 count rising from 94 to 160 cells/mm3; the lip lesions developed approximately two months after the CD4 count began to improve. He had received multiple courses of antibiotics and systemic corticosteroids without benefit. He was taking acyclovir for herpes simplex prophylaxis and dapsone for Pneumocystis jiroveci prophylaxis. | |
| On examination, his lips were markedly edematous, with multiple superficial ulcers having heaped?up margins. There was no hepatosplenomegaly. The initial differential diagnosis included herpetic ulcers, bacterial infection, fungal infection, and angioedema. | |
| Diagnostic studies showed an undetectable HIV viral load and undetectable hepatitis C viral load. A polymerase?chain?reaction assay for herpes simplex virus from an ulcer base was negative. Complement C1 esterase inhibitor levels were within normal limits. Gram stain, acid?fast stain, and mucicarmine stain of lesion samples were negative. Fungal blood cultures and both urine and serum Histoplasma antigen tests were negative.",Histoplasmosis "A 65-year-old man with hypertension, diabetes mellitus, and bronchial asthma presented with mild headaches of several months� duration and no focal neurologic deficits. He had undergone cranial MRI 4 years earlier for unrelated reasons, with no significant change in the identified lesion since then. Laboratory studies were normal. Noncontrast CT of the head revealed a well-defined, 19-mm mass in the left parietal bone near the squamosal suture, centred in the diploic space, with sparse but preserved trabeculae and a slight bony bulge, without disruption of the inner or outer tables. MRI showed the lesion to be isointense to muscle on T1-weighted images, with multiple internal hyperintense foci, heterogeneous signal on T2-weighted images, and restricted diffusion. The hyperintense foci on T1 images were presumed to represent bone marrow fat, and the preserved trabecular architecture suggested that pre-existing structures were not destroyed.",intraosseous metaplastic meningioma | |