Skin Cancer & Dermatology Experts
Squamous cell skin cancer is the second most common type of skin cancer. It arises from squamous cells which form the outer layer of the epidermis (the top layer of skin). Squamous cell carcinoma can occur anywhere on the skin including mucous membranes and genitals but is most common on areas frequently exposed to the sun including the rim of the ear, lower lip, the face, bald scalp, neck, arms, hands and legs. It often appears as an opaque or red scaling patch or a firm bump in sun-exposed areas, and may be mistaken for a wart or patch of dry skin.
Unlike basal cell carcinoma, squamous cell carcinoma, if left to grow, can progress far enough to get into the lymph nodes and blood stream and become a threat to a patient's life. This is more common in large, aggressive squamous cell carcinomas, cancers occurring on the ears, upper head, lips and genitalia or skin cancers that have been treated before, but have now come back. The overall chance of any squamous cell carcinoma spreading outside the local region is about 2%, but this can be much higher depending on the location of the cancerous site or other features. Therefore, it is important to get early treatment.
Image used with permission of the American Academy of Dermatology National Library of Dermatologic teaching slides. ©2005 America Academy of Dermatology
