Overview for patients
Skin cancer is the most common type of cancer and it usually forms in skin that has been exposed to sunlight, but can occur anywhere on the body. Skin cancer begins in the epidermis (outer layer), which is made up of squamous cells, basal cells, and melanocytes.
Squamous cell and basal cell skin cancers are sometimes called nonmelanoma skin cancers and usually respond to treatment and rarely spread to other parts of the body.
Melanoma is more aggressive type of skin cancer. If it isn’t diagnosed early, it is likely to invade nearby tissues and spread to other parts of the body.
Rare types of skin cancer include Merkel cell carcinoma, skin lymphoma, and Kaposi sarcoma.