The most common types of nonmelanoma skin cancer include basal cell carcinoma and squamous cell carcinoma.
Basal cells comprise the lower portion of your top layer of skin (epidermis) called the basal cell layer. Basal cell carcinoma typically occurs in areas that receive a high level of exposure to the sun, such as your face, neck and the top of your hands. It generally grows slowly, but if left untreated, it can invade surrounding tissue or spread to other organs.
Squamous cell carcinoma develops in the epidermis when squamous cells divide abnormally. This occurs in skin areas that receive high sun exposure, such as your face, neck and the top of your hands. Squamous cell carcinoma can spread to lymph nodes and internal organs, but spreading is not common. People who have squamous cell carcinomas on the face, particularly the lip and ear, are at higher risk of the cancer spreading, as are those whose immune systems are suppressed or who have had organ transplants.
Other less common types of nonmelanoma skin cancer include Merkel cell carcinoma, dermatofibrosarcoma protuberans (DFSP), microcystic adnexal carcinoma, atypical fibroxanthoma (AFX), malignant fibrous histiocytoma, sebaceous carcinoma and other rare adnexal tumors.