Kaposi's sarcoma is a cancerous tumor of the connective tissue, and is often associated with AIDS.

Before the AIDS epidemic, Kaposi's sarcoma was seen primarily in elderly Italian and Jewish men, and rarely, in elderly women. Among this group, the tumors developed slowly. In AIDS patients, the cancer can develop very fast, and may also involve the skin, lungs, gastrointestinal tract, and other organs.

In people with AIDS, Kaposi's sarcoma is caused by an interaction between HIV, a weakened immune system, and the human herpesvirus-8 (HHV-8). Occurrence of Kaposi's sarcoma has been linked to the spread of HIV and HHV-8 through sexual activity.

People who have kidney transplants are also at risk for Kaposi's sarcoma.

African Kaposi's sarcoma is fairly common in young adult males living near the equator. One form is also common in young African children.

The tumors appear as bluish-red or purple lesions on the skin. They may first appear on the feet or ankles, thighs, arms, hands, face, or any other part of the body.

Other symptoms may include:

• Bleeding from gastrointestinal lesions
• Shortness of breath from lesions in the lung
• Bloody sputum from lesions in the lung

The following tests may be performed to diagnose Kaposi's sarcoma:

• Skin lesion biopsy
• Endoscopy