All three types of cancer begin in the cells of the epidermis, the skin's upper layer.
Basal cell carcinoma may have slightly raised edges with a crusty, indented center. This type of skin cancer grows very slowly and usually does not spread to other parts of the body. It is usually treated by removing the tumor (with surgery) or by freezing the tumor (cryotherapy).
Squamous cell carcinoma is the second most common type of skin cancer in fair-skinned people. It is twice as common in men as in women. Like other skin cancers, squamous cell carcinoma is caused by too much exposure to UV rays from the sun or indoor tanning booths. It may appear as a bump or scaly red patch on the face, neck, arms, scalp, ear, lips, or mouth. Squamous cell carcinoma is a slow-growing cancer but it can spread to other parts of the body. Because this cancer can spread, it is important to treat it as early as possible through surgery or radiation therapy.
Melanoma is the least common type of skin cancer, but is the most serious. It begins in the melanocytes. These are the skin cells that make the pigment called melanin, which gives skin its color. Melanoma can quickly spread to other parts of the body so it is important to detect and treat melanoma in its early stages. Melanoma is the leading cause of all skin cancer-related deaths.