Basal Cell Carcinoma

Commonest form of skin cancer
Slow growing tumour affecting the basal cells of the skin
Can locally invade but rarely metastasises
Can sometimes be referred to by laymen as "rodent ulcer"

Epidemiology

Accounts for 80% of non-melanoma skin cancers
80% of cases occur in the head and neck ^[1]
Marked geographical variation (commonest in Europe, Australia and USA)
Much more common in fair-skinned individuals with a family history
Up to 30% of caucasians will develop BCCs in their lifetime ^[1]
Incidence increases in those >50 years old
Multiple BCCs in younger patients is suggestive of nevoid basal-cell carcinoma syndrome (Gorlin-Goltz Syndrome)
♀ > ♂

Clinical Features

Most commonly affects sun exposed areas
Different subtypes exist which tend to occur at different anatomical locations (see below for main types)
Pigmented subtype also exists (~7% of cases)^[2]

Clinical subtypes
Type	Clinical	Notes
Nodular	Nodular Pearly white or pink Telangiectasia Ulceration Cystic is a variant of nodular BCC Appears as a smooth, round cystic mass	Most common form
Morphoeic (Sclerosing)	Usually found in mid-facial sites Waxy, scar-like plaque with indistinct borders Wide and deep subclinical extension May infiltrate cutaneous nerves (perineural spread)	The most important clinical subtype 5% of all BCCs More aggressive and ill-defined ∴ complete excision is more difficult Can be very large and pose reconstructive issues
Superficial	Slightly scaly, irregular plaque Thin, translucent rolled border Multiple microerosions	Most common type in younger adults Most common type on upper trunk and shoulders

Differential Diagnosis

Squamous Cell Carcinoma
Malignant melanoma (pigmented basal cell carcinoma)
Melanocytic naevi (pigmented basal cell carcinoma)
Bowen's disease (especially superficial basal cell carcinoma)
Psoriasis (superficial)
Eczema (superficial)
Sebaceous hyperplasia
Molluscum contagiosum
Appendygeal tumours

Aetiology and Pathogenesis

Risk factors
- Ultraviolet (UV) light exposure from sun/sun-beds, especially in childhood ^[3]
- History of previous skin cancers
- Genetic predisposition/association with fair skin type
- Immunosuppression (post-transplant, anti-TNF drugs [infliximab], haematological malignancies)
- Nevoid basal-cell carcinoma syndrome (Gorlin-Goltz Syndrome)
- Xeroderma pigmentosum
Pathogenesis

Investigations

Diagnosis is usually clinical
In cases where there is uncertainty an incisional or punch biopsy may be performed

Imaging

CT or MRI imaging may be used for extensive lesions to delineate any involvement in adjacent structures

Management

Management

Prognosis and Complications

Prognosis and Complications

References

[Wong-1] 1.0 ^1.1 Wong CS, Strange RC, Lear JT. Basal cell carcinoma. Bmj. 2003 Oct 2;327(7418):794-8.

[pBCC-2] Maloney ME, Jones DB, Sexton FM. Pigmented basal cell carcinoma: investigation of 70 cases. Journal of the American Academy of Dermatology. 1992 Jul 1;27(1):74-8.

[Corona-3] Corona R, Dogliotti E, D'Errico M, Sera F, Iavarone I, Baliva G, Chinni LM, Gobello T, Mazzanti C, Puddu P, Pasquini P. Risk factors for basal cell carcinoma in a Mediterranean population: role of recreational sun exposure early in life. Archives of dermatology. 2001 Sep 1;137(9):1162-8.

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