Uncommon types of skin cancer include Kaposi's sarcoma, mainly seen in people with weakened immune systems; Merkel cell carcinoma, which is usually found on sun-exposed areas on the head, neck, arms and legs but often spreads to other parts of the body; and sebaceous gland carcinoma, an aggressive cancer originating in the oil glands in the skin.
Must-See Slideshow
Slideshow: Precancerous Skin Lesions and Skin Cancer Picture Slideshow