Squamous Cell Carcinoma

Squamous cell cancer may occur in normal skin or in skin that has been injured or inflamed. Most skin cancers occur on skin that is regularly exposed to sunlight or other ultraviolet radiation.

The earliest form of squamous cell skin cancer is called Bowen’s disease (or squamous cell in-situ). This type of squamous cell carcinoma is in the epidermis (top layer of the skin) and has not yet invaded into the dermis (deeper layer of skin).

Squamous cell carcinoma is the second most common type of skin cancer. Each year in the United States, over 250,000 cases of invasive squamous cell carcinomas are diagnosed. About 65% of squamous cell carcinomas occur on the head and neck. Currently, it is estimated that one in every five Americans will develop skin cancer during their lifetime; many of which are squamous cell carcinoma.

Actinic keratosis is a precancerous skin lesion that may become a squamous cell cancer if left untreated. Approximately 10% of actinic keratosis will develop into a squamous cell carcinoma if not treated.