Squamous Cell Carcinoma & Precursors

Key points

• SCC: keratinising/crusted nodule or ulcer on sun-damaged skin; CAN metastasise (especially lip, ear, immunosuppressed).
• Actinic (solar) keratosis: rough scaly patches on sun-exposed skin — premalignant; treat with cryotherapy/5-FU/imiquimod/diclofenac gel.
• Bowen's disease: SCC in situ — well-defined scaly plaque.
• Keratoacanthoma: rapidly growing volcano-like nodule — may regress but usually excised.
• Transplant/immunosuppressed patients have markedly increased SCC risk.