[Epidermoid (or squamous cell) carcinoma]

Cutaneous epidermoid carcinomas are common cancers that most often affect people who are elderly or immunocompromised. They may occur anywhere but are found most often on photoexposed areas because UV rays are a major risk factor for them. They often develop on precancerous lesions of the skin (actinic keratosis) but also of the mucous membranes (HPV-induced infections or lichen). Their particular clinical presentation depends on their site and their cause. Prognosis is generally good when surgical excision is performed early with a sufficient margin of healthy tissue. Nonetheless, some advanced forms or with histologic criteria indicating poor prognosis have a risk of lymph node or distant metastasis and may require more intense treatment. Their prevention is based on photoprotection and on dermatologic surveillance of at-risk subjects.