Kaposi's sarcoma is a cancer of the walls of the blood vessels or lymphatic system; it may also affect other body tissues, including the throat, lungs, and gastrointestinal tract. It usually appears as pink to purple spots or bumps on the skin or mucous membranes.

Although Kaposi's sarcoma is rare, it is more common in people who have impaired immune systems, such as people who have HIV infection or AIDS. In the past, the disease mostly affected older people of Mediterranean descent.

Kaposi's sarcoma may be treated with radiation or chemotherapy.