Epidemiology: Second most common form of skin cancer after basal cell carcinoma

Risk factors:- Sun exposure (especially among fair-skinned individuals)- Exposure to ionizing radiation- Exposure to chemical carcinogens (e.g., coal tars through smoking, arsenic)- Chronic scars/wounds/burn injuries- Chronic immunosuppression (e.g., HIV, transplant patients who receive immunosuppressive therapy)- Precancerous skin lesions (especially actinic keratosis and Bowen's disease)

Clinical features:- Initial appearance may be plaque-like, nodular, papillomatous, and/or verrucous- All forms eventually ulcerate.→ The ulcer typically has everted edges.→ The floor of the ulcer resembles granulation tissue and bleeds easily.→ The skin around the ulcer is inflamed and indurated.- Most commonly on the face and neck; a typical location is the lower lip.- Locally invasive but grows slowly.- The overall rate of metastasis is 2%.

Subtype: Marjolin's ulcer = an aggressive form of cSCC that typically develops from areas of chronically damaged skin such as ulcers (e.g., pressure ulcers, osteomyelitis) and scars (e.g., burn scars)

Diagnosis: Clinical, confirm with shave biopsy

Treatment: - Surgical excision or Mohs microscopic surgery- Radiotherapy- Chemotherapy (e.g., 5-fluorouracil, epidermal growth factor inhibitors)