Squamous cell carcinoma is the second most common skin cancer after basal cell carcinoma. Squamous cell cancers may occur on all areas of the body including mucous membranes, but are most common in areas exposed to the sun. In a small percentage of cases it spreads (metastasize) to distant tissues and organs. When this happens, squamous cell carcinoma can be fatal. Chronic exposure to sunlight causes most cases of squamous cell carcinoma. That is why tumors appear most frequently on sun-exposed parts of the body: the face, neck, bald scalp, hands, shoulders, arms, and back. The rim of the ear and the lower lip are especially vulnerable to the development of these cancers. Squamous cell carcinomas have varying characteristics, including: a wart-like growth that crusts and occasionally bleeds; a persistent, scaly red patch with irregular borders that sometimes crusts or bleeds; an open sore that bleeds and crusts and persists for weeks; an elevated growth with a central depression that occasionally bleeds. Ask your Oral & Maxillofacial Surgeon about suspected areas on your face or in your mouth.