Squamous cell carcinoma is a slow-growing type of cancer that affects the outer layers of the skin.
Normal cells divide in an orderly way, making more cells only when needed.
But when cancer develops, the cells begin to grow and divide without restraint, often forming a lump or bump called a tumor. In many types of cancer, the diseased cells spread to other parts of the body. Fortunately, basal cancer cells usually do not. Like other types of skin cancer, it usually doesn't appear before age 40. Sun lamps and tanning booths that use man-made UV rays are also a threat.