AKT · Dermatology/Malignant & pre-malignant

Basal cell carcinoma

Malignancy of basal keratinocytes (UV-driven)

Overview

The commonest skin cancer — a slow-growing, locally invasive malignancy of basal keratinocytes that virtually never metastasises. The classic nodular BCC is a pearly papule with a rolled telangiectatic edge and central ulceration ("rodent ulcer") on sun-exposed skin of older adults.

Recognise

Pearly/translucent papule or nodule with a rolled border and surface telangiectasia, slowly enlarging on the face/head/neck
May ulcerate centrally (rodent ulcer); bleeds with minor trauma and fails to heal
Subtypes: nodular, superficial (erythematous scaly patch on the trunk), morphoeic/infiltrative (scar-like, ill-defined, higher-risk)

Red flags

Recurrent, large, morphoeic/infiltrative, or high-risk-site (central face, around eyes/nose/ears) lesions need careful margin control (Mohs)

Differentials & how to tell them apart

Squamous cell carcinomafaster-growing, keratotic/tender, can metastasise — BCC is pearly and slow

Sebaceous hyperplasiasoft yellowish papule with a central dell, no ulceration

Intradermal naevuslong-standing soft skin-coloured papule, no telangiectasia/ulceration

Amelanotic melanomacan mimic — biopsy any uncertain enlarging lesion

Clinical image

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Basal cell carcinoma — clinical imagesDermNet

Investigations

Clinical ± dermoscopy; diagnostic/excision biopsy. Routine (non-2-week-wait) dermatology referral — BCC rarely metastasises, so it does not use the suspected-cancer fast track.

Management

Surgical excision (Mohs for high-risk facial sites)

1Routine dermatology referral (not the 2-week-wait pathway). Confirm and treat by surgical excision with appropriate margins.Gate: BCC is referred ROUTINELY, not on the suspected-cancer 2-week-wait pathway, because it essentially never metastasises — reserve the fast track and Mohs for higher-risk/facial lesions
2Superficial low-risk BCC → topical imiquimod/5-FU, cryotherapy, curettage or PDT. High-risk/recurrent/critical-site → Mohs micrographic surgery; advanced disease → vismodegib.

Surgical excision — first-line for most BCCs (standard margins; Mohs for high-risk/facial)

Topical imiquimod or 5-fluorouracil — superficial BCC

Cryotherapy / curettage / photodynamic therapy — low-risk superficial lesions

Vismodegib (hedgehog inhibitor) — locally advanced/inoperable disease (specialist)

Key points

BCC is locally destructive but does not metastasise — hence routine referral. The central face/eyes/nose/ears are high-risk sites favouring Mohs. Lifelong sun protection and surveillance for further skin cancers.

Monitor & prognosis

Surveillance for recurrence and new skin cancers.

Excellent — cure rates are very high with complete excision.

Source: NICE NG12 (suspected cancer); BAD BCC guideline