Squamous cell skin cancer is a type of tumor that affects the skin.

Squamous cell cancer results when cells in the skin start to change. The changes may begin 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. Skin cancer is most often seen in people over age 50.

Risks for squamous cell skin cancer include:

• A large number of x-rays
• Arsenic
• Chemical exposure
• Exposure to sunlight and ultraviolet radiation
• Having light-colored skin, blue or green eyes, or blond or red hair
• Older age

Squamous cell cancer spreads faster than basal cell cancer, but still may be relatively slow-growing. It can spread (metastasize) to other locations, including internal organs.

See also: Actinic keratosis

The main symptom of squamous cell skin cancer is a growing bump that may have a rough, scaly surface and flat reddish patches.

The bump is usually located on the face, ears, neck, hands, or arms, but may occur on other areas.

A sore that does not heal can be a sign of squamous cell cancer. Any change in an existing wart, mole, or other skin lesion could be a sign of skin cancer.

A lesion on the skin may indicate a squamous cell carcinoma. A biopsy and examination of the lesion can confirm whether it is squamous cell cancer.