Introduction

Squamous cell carcinoma is a non-melanoma skin cancer (NMSC) and the second most common type of skin cancer in the UK after basal cell carcinoma. It is also known as cutaneous squamous cell carcinoma referring specifically to the skin and is commonly abbreviated to SCC. It is formed on the flat squamous cells on the outermost layer of skin, the epidermis and is found on sun-exposed areas of skin such as face, lips, ears, hands, forearms and lower legs. It can be invasive and metastasise. 

Clinically, it often presents as an irregular, keratinous nodule or a firm erythematous plaque that frequently ulcerates which can grow quickly. Often patients have pre-existing actinic keratosis or Bowen’s disease (intraepidermal squamous cell carcinoma).

Long term sun exposure is biggest risk factor, however other risk factors for development of SCC include male sex, immunosuppression including transplant patients, exposure to chemical carcinogens, ionizing radiation, scarred skin, infection with specific HPV subtypes and history of other skin cancers.

Treatment is surgical and an excision includes usually a 3-4mm margin of normal tissue around a visible tumour with flaps or grafts sometimes needed. Other methods of removal include shave, curettage and cautery, cryotherapy (if small and low risk), Mohs micrographic surgery and radiotherapy.

It is important to know the common features of SCC macroscopically as traditionally SCC can be more difficult to tell via dermatoscope.