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

Treatment decisions depend on the extent and location of the lesions, as well as the person's symptoms and degree of immunosuppression. Antiviral therapy against the AIDS virus can shrink the lesions.

Radiation therapy or cryotherapy can be used for lesions in certain areas. Combination chemotherapy may also be used. However, lesions may return after treatment.

Treatment and remission of Kaposi's sarcoma does not improve the chances of survival from AIDS itself. The outlook depends on the immune status and HIV viral load of the patient.

Kaposi's sarcoma can involve the lungs and cause significant symptoms, including cough and shortness of breath. This diagnosis is made by a CT scan of the chest and a bronchoscopy. The tumors can return even after apparently successful treatment. Kaposi's sarcoma can be fatal for a person with AIDS.

An aggressive form of African Kaposi's sarcoma can spread quickly to the bones. Another form found in African children does not affect the skin. Instead, it spreads through the lymph nodes and vital organs, and can quickly become fatal.

Safe sexual practices can prevent infection with HIV, which in turn prevents the development of AIDS and its complications, including Kaposi's sarcoma.