Squamous cell carcinoma
These cancers are the second most common type of skin cancer, accounting for approximately 20 percent of non-melanoma skin cancers. They develop from the flat squamous cells that make up much of epidermis, the outermost layer of the skin.
This type of skin cancer is usually found on areas of the skin that have been exposed to the sun, such as the neck, ears, face or the back of the hand, but they may develop in other areas, such as in scars, skin ulcers or the genital region. Squamous cell cancers usually grow slowly, and it is uncommon for them to spread, or metastasize. But they are more likely than basal cell carcinomas to invade fatty tissue beneath the skin or to spread even further.