knowledge_docs/bcc.txt

# Basal Cell Carcinoma (bcc)
Source: DermNet NZ (dermnetnz.org)


## Source: https://dermnetnz.org/topics/basal-cell-carcinoma

Authors: Honorary Associate Professor Amanda Oakley, Dermatologist, New Zealand (1997); Minor update: Dr Anthony Martin Fuentes, General Practitioner and Cosmetic Doctor, Hospital Jose Molina Orosa, Spain (2025) Update peer reviewed by: Dr Andjela Arandjelovic, Dermatology Clinical and Trials Research Fellow, Royal Melbourne Hospital, Australia (2025)

Reviewing dermatologist: Dr Ian Coulson Edited by the DermNet content department.

Introduction Demographics Causes Clinical features Types of BCC Complications Diagnosis Treatment for primary basal cell carcinoma Treatment for advanced basal cell carcinoma Prevention Outlook

Basal cell carcinoma (BCC) is a common, locally invasive , keratinocyte cancer (also known as nonmelanoma cancer ). It is the most common form of skin cancer . BCC is also known as rodent ulcer and basalioma. Patients with BCC often develop multiple primary tumours over time.

BCC is also known as rodent ulcer and basalioma.

Age and sex : BCCs are particularly prevalent in elderly males. However, they also affect females and younger adults

Previous BCC or other form of skin cancer ( squamous cell carcinoma , melanoma )

Sun damage ( photoageing , actinic keratoses )

Fair skin, blue eyes and blond or red hair — note; BCC can also affect darker skin types

Previous cutaneous injury, thermal burn , disease (eg cutaneous lupus , sebaceous naevus )

Inherited syndromes: BCC is a particular problem for families with basal cell naevus syndrome ( Gorlin syndrome ), Bazex-Dupré-Christol syndrome , Rombo syndrome, Oley syndrome and xeroderma pigmentosum

Other risk factors include ionising radiation, exposure to arsenic , immune suppression due to disease or medicines , and use of some other medicines such as hydrochlorothiazide.

Most often, there are DNA mutations in the patched (PTCH) tumour suppressor gene , part of the hedgehog signalling pathway.

These may be triggered by exposure to ultraviolet radiation .

Various spontaneous and inherited gene defects predispose to BCC.

What are the clinical features of basal cell carcinoma?

BCC is a locally invasive skin tumour. The main characteristics are:

Varies in size from a few millimetres to several centimetres in diameter

BCC is very rarely a threat to life. A tiny proportion of BCCs grow rapidly, invade deeply, and/or metastasise to local lymph nodes.

See also: Basal cell carcinoma in skin of colour

There are several distinct clinical types of BCC, and over 20 histological growth patterns of BCC.

Shiny or pearly nodule with a smooth surface

May have central depression or ulceration, so its edges appear rolled

Cystic variant is soft, with jelly-like contents

Micronodular, microcystic and infiltrative types are potentially aggressive subtypes

Most common type on the upper trunk and shoulders

Waxy, scar-like plaque with indistinct borders

May infiltrate cutaneous nerves ( perineural spread)

Also known as morpheic, morphoeiform or sclerosing BCC

Mixed basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)

Potentially more aggressive than other forms of BCC

Also known as basosquamous carcinoma and mixed basal- squamous cell carcinoma

What are the complications of basal cell carcinoma?

Recurrence of BCC after initial treatment is not uncommon. Characteristics of recurrent BCC often include:

Incomplete excision or narrow margins at primary excision

Morphoeic, micronodular, and infiltrative subtypes

Advanced BCCs are large, often neglected tumours.

They may be several centimetres in diameter

They may be deeply infiltrating into tissues below the skin

They are difficult or impossible to treat surgically

Primary tumour is often large, neglected or recurrent, located on head and neck, with aggressive subtype

May arise in-site exposed to ionising radiation

BCC is diagnosed clinically by the presence of a slowly enlarging skin lesion with typical appearance.

Arborizing vessels ( telangiectasia with tree-like branching)

Additional criteria for non-pigmented, superficial BCC:

Non-classical vascular patterns (hairpin, glomerular, dotted, comma).

Shiny white lines — tend to be disorganised or arranged in parallel

Stellate pattern — from the visible tumour edge; may be formed by white lines, vessels, or uneven skin surfaces

Multiple aggregated yellow-white (MAY) globules.

The diagnosis and histological subtype is usually confirmed pathologically by a diagnostic biopsy or following excision . See: basal cell carcinoma pathology .

While histology remains the gold standard for BCC subtyping, non-invasive optical techniques like line-field confocal optical coherence tomography (LC-OCT) are increasingly utilized for BCC diagnosis and monitoring. LC-OCT has proven its effectiveness in real-world settings, enabling early detection, minimizing unnecessary biopsies , and providing valuable insights into disease progression, especially in cases where surgery is not indicated.

What is the treatment for primary basal cell carcinoma?

The treatment for a BCC depends on its type, size and location, the number to be treated, patient factors, and the preference or expertise of the doctor. Most BCCs are treated surgically. Long-term follow-up is recommended to check for new lesions and recurrence; the latter may be unnecessary if histology has reported wide clear margins.

Excision means the lesion is cut out and the skin stitched up.

Most appropriate treatment for nodular, infiltrative and morphoeic BCCs.

Should include 3 to 5 mm margin of normal skin around the tumour.

Very large lesions may require flap or skin graft to repair the defect.

A pathologist will report deep and lateral margins.

Further surgery is recommended for lesions that are incompletely excised.

Mohs micrographically controlled excision

Mohs micrographically controlled surgery involves examining carefully marked excised tissue under the microscope , layer by layer, to ensure complete excision.

Very high cure rates achieved by trained Mohs surgeons.

Used in high-risk areas of the face around eyes, lips, and nose.

Suitable for ill-defined, morphoeic, infiltrative and recurrent subtypes.

Large defects are repaired by flap or skin graft .

Superficial skin surgery comprises shave, curettage , and electrocautery . It is a rapid technique using local anaesthesia and does not require sutures .

Suitable for small, well-defined nodular or superficial BCCs.

Lesions are usually located on the trunk or limbs.

Wound is left open to heal by secondary intention .

Moist wound dressings lead to healing within a few weeks.

Cryotherapy is the treatment of a superficial skin lesion by freezing it, usually with liquid nitrogen.

Suitable for small superficial BCCs on covered areas of the trunk and limbs.

Best avoided for BCCs on head and neck, and distal to knees.

Results in a blister that crusts over and heals within several weeks.

Photodynamic therapy (PDT) refers to a technique in which BCC is treated with a photosensitising chemical, and exposed to light several hours later.

Topical photosensitisers include aminolevulinic acid lotion and methyl aminolevulinate cream .

Suitable for low-risk small, superficial BCCs.

Best avoided if tumour in-site at high risk of recurrence.

Results in inflammatory reaction, maximal 3–4 days after procedure.

Treatment repeated 7 days after initial treatment.

Imiquimod is an immune response modifier.

Best used for superficial BCCs less than 2 cm diameter.

Applied three to five times each week, for 6–16 weeks.

Results in a variable inflammatory reaction, maximal at three weeks.

5-Fluorouracil cream is a topical cytotoxic agent.

Used to treat small superficial basal cell carcinomas.

Requires prolonged course, eg twice daily for 6–12 weeks.

Radiotherapy or X-ray treatment can be used to treat primary BCCs or as adjunctive treatment if margins are incomplete.

Best avoided in young patients and in genetic conditions predisposing to skin cancer.

Best cosmetic results achieved using multiple fractions.

Typically, patient attends once-weekly for several weeks.

Causes inflammatory reaction followed by scar.

Risk of radiodermatitis , late recurrence, and new tumours.

What is the treatment for advanced or metastatic basal cell carcinoma?

Locally advanced primary, recurrent or metastatic BCC requires multidisciplinary consultation. Often a combination of treatments is used.

Targeted therapy refers to the hedgehog signalling pathway inhibitors , vismodegib and sonidegib . These drugs have some important risks and side effects.

How can basal cell carcinoma be prevented?

The most important way to prevent BCC is to avoid sunburn . This is especially important in childhood and early life. Fair-skinned individuals and those with a personal or family history of BCC should protect their skin from sun exposure daily, year-round and lifelong.

Stay indoors or under the shade in the middle of the day.

Apply high protection factor SPF50+ broad-spectrum sunscreens generously to exposed skin if outdoors.

Oral nicotinamide (vitamin B3) in a dose of 500 mg twice daily may reduce the number and severity of BCCs.

What is the outlook for basal cell carcinoma?

Most BCCs are cured by treatment. Cure is most likely if treatment is undertaken when the lesion is small.

About 50% of people with BCC develop a second one within 3 years of the first. They are also at increased risk of other skin cancers , especially melanoma . Regular self-skin examinations and long-term annual skin checks by an experienced health professional are recommended.

Álvarez-Salafranca M, Ara M, Zaballos P. Dermoscopy in Basal Cell Carcinoma: An Updated Review. Advances in Dermatology. 2021; doi: 10.1016/j.ad.2020.11.011. Journal

Barbarossa L, D’Onghia M, Cartocci A, Suppa M, Tognetti L, Cappilli S, Peris K, Perez-Anker J, Malvehy J, Baldino G, et al. Understanding the Dermoscopic Patterns of Basal Cell Carcinoma Using Line-Field Confocal Tomography. Tomography. 2024; 10(6):826-838. https://doi.org/10.3390/tomography10060063. Journal

Kim DP, Kus KJB, Ruiz E. Basal Cell Carcinoma Review. Head & Neck Oncology. 2018;10(1):21. doi: 10.1016/j.hoc.2018.09.004. Journal

Menzies SW, Westerhoff K, Rabinovitz H, Kopf AW, McCarthy WH, Katz B. Surface Microscopy of Pigmented Basal Cell Carcinoma. Arch Dermatol. 2000;136(8):1012–1016. doi:10.1001/archderm.136.8.1012. Journal

Wojtowicz I, Żychowska M. Dermoscopy of Basal Cell Carcinoma Part 1: Dermoscopic Findings and Diagnostic Accuracy-A Systematic Literature Review. Cancers (Basel). 2025;17(3):493. Published 2025 Feb 1. doi:10.3390/cancers17030493. Journal

Work Group; Kim JYS, Kozlow JH, Mittal B, Moyer J, Olencki T, Rodgers P. Guidelines of care for the management of basal cell carcinoma. J Am Acad Dermatol. 2018;78(3):540-559. doi: 10.1016/j.jaad.2017.10.006. Journal

Basal cell carcinoma — common skin lesions course | Basal cell carcinoma dermoscopy | Genetics of basal cell carcinoma | Basal cell carcinoma pathology | Basal cell carcinoma in skin of colour

Dermatological procedures | Mohs micrographic surgery | Targeted cancer therapy

Skin cancer | Skin lesions | Vulval cancer

Skin cancers and precancers — DermNet e-lecture [Youtube]

Clinical practice guidelines for keratinocyte cancer — Cancer Guidelines wiki

American College of Mohs Micrographic Surgery and Oncology

Mohs Micrographic Surgery from Johns Hopkins Oncology Center

Basal cell carcinoma : emedicine dermatology, the online medical reference textbook.

Basal cell carcinoma — British Association of Dermatologists

Optimal care pathway for people with basal cell carcinoma or squamous cell carcinoma — Cancer Council of Australia, June 2016

Basal cell carcinoma — American Academy of Dermatology