Kaposi's sarcoma produces pink, purple, or brown tumors on the skin, mucous membranes, or internal organs. It was a very rare form of cancer, primarily affecting elderly men of Mediterranean and eastern European background, until the 1980s, when it began to appear among AIDS patients. Milder forms of the disease can be managed successfully with topical agents and therapies; widespread disease requires chemotherapy.

Investigators recognize four distinct forms of Kaposi's sarcoma (KS). The first form, called classic KS, was described by the Austrian dermatologist Moriz Kaposi more than a century ago. Classic KS usually affects older men of Mediterranean or eastern European backgrounds by producing tumors on the lower legs. Though at times painful and disfiguring, they are not generally life-threatening. The second form of the disease, African endemic KS, primarily affects boys and men. It can appear as classic KS, or in a more deadly...