PassFinals
Dermatology

Non-melanoma skin cancer

Non-melanoma skin cancer mainly comprises basal cell carcinoma and cutaneous squamous cell carcinoma; distinguish their behaviour, refer appropriately and treat histologically confirmed disease according to site and risk.

In a nutshell

BCC is usually locally destructive and slow-growing; cSCC is more likely to invade and metastasise. Recognise lesions, use NICE referral urgency, confirm uncertain disease histologically, treat according to site/subtype/risk and safety-net recurrence.

Classic presentation

Persistent non-healing pearly ulcer or nodule for BCC; scaly, keratotic, indurated or rapidly growing lesion for cSCC on sun-exposed skin.

Key points

  • NICE: suspected cSCC merits suspected-cancer referral; typical BCC is usually non-urgent unless site/size makes delay important.
  • BCC rarely metastasises but can cause major local destruction, especially around eyes, nose, ears and lips.
  • cSCC risk rises with size, depth, poor differentiation, perineural invasion, recurrence, high-risk site and immunosuppression.
  • Actinic keratosis and Bowen disease are keratinocyte precursor/in-situ lesions; invasion changes management.
  • Histology is needed when diagnosis, subtype, invasion or treatment choice is uncertain.
  • High-risk/recurrent lesions need specialist dermatology/plastic/head-and-neck/oncology MDT assessment and sometimes margin-controlled surgery or radiotherapy.
  • Sun protection and surveillance matter because additional lesions are common.

First-line investigation

Focused skin and regional-node examination, followed by dermoscopy/specialist biopsy when indicated.

Management

Assess and refer

  • Use lesion morphology, site, host risk and NICE NG12 urgency; suspected cSCC needs suspected-cancer referral, while BCC urgency depends on site/size.4

Confirm diagnosis

  • Use trained dermoscopy and biopsy/excision when histology, invasion or subtype is uncertain.1,2

Treat low-risk lesions appropriately

  • Choose BCC/cSCC/SCC-in-situ treatment according to subtype, risk, site, margins, cosmetic impact and local specialist guidance.1,2,3

Refer high-risk or advanced disease

  • Use specialist MDT review for recurrent, aggressive, perineural, nodal, metastatic or difficult-site disease.1,2

Prevent further damage

  • Advise sun protection, avoid tanning, inspect skin and address immunosuppression risk with the relevant specialist.1,2,5

Surveil for recurrence and new lesions

  • Use risk-specific follow-up and safety-net a new, changing, bleeding, painful or non-healing lesion.1,2,5

Exam traps

  • BCC can be destructive despite low metastatic risk.
  • A rough scaly lesion can be actinic keratosis, Bowen disease or invasive cSCC—do not assume.
  • A lesion on the nose/eyelid/ear or in a scar is not automatically low risk.
  • Clinical improvement with a cream does not prove cancer is absent.

Illustrations

Dermoscopy of nodular basal cell carcinomaDermoscopic image of a nodular basal cell carcinoma showing branching (arborising) telangiectatic vessels over a translucent pink background, a characteristic feature.David.moreno72, Wikimedia Commons · CC-BY-SA-4.0
Squamous cell carcinoma histology with keratin pearlsHaematoxylin and eosin section showing invasive nests of atypical keratinocytes with concentric keratin pearls, typical of well-differentiated cutaneous squamous cell carcinoma.LWozniak&KWZielinski, Wikimedia Commons · CC-BY-SA-3.0
Keratinocyte UV damage pathwayDiagram contrasting basal-layer origin of BCC with the actinic keratosis-to-SCC progression from more superficial keratinocytes.PassFinals · original
Actinic keratosisClinical photograph of a rough, scaly, erythematous patch on sun-exposed skin, the premalignant precursor to cutaneous squamous cell carcinoma.James Heilman, MD, Wikimedia Commons · CC-BY-SA-4.0

Key sources

  1. British Association of Dermatologists: Basal cell carcinoma guideline 2021 (UK management guideline for adults with BCC)Published 1 Nov 2021
  2. British Association of Dermatologists: Cutaneous squamous cell carcinoma guideline 2020 (UK management guideline for cutaneous SCC)Published 1 Mar 2021
  3. British Association of Dermatologists: Squamous cell carcinoma in situ (Bowen disease) guideline 2022 (UK management guidance for SCC in situ)Published 10 Feb 2023
  4. NICE NG12: Suspected cancer recognition and referral — skin cancer (Referral criteria for melanoma, SCC and BCC)Published 23 Jun 2015 | Updated 15 Apr 2026
  5. NHS: Skin cancer (Public-facing symptoms, prevention and safety-netting information)

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.