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 mainly 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. It 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). Kaposi's sarcoma has been linked to the spread of HIV and HHV-8 through sexual activity.

People who have kidney or other organ 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 sores (lesions) on the skin. The color comes from the fact that they are rich in blood vessels.

The lesions may first appear on the feet or ankles, thighs, arms, hands, face, or any other part of the body. They also can appear on sites inside the body.

Other symptoms may include:

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

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

• Bronchoscopy
• CT scan
• Endoscopy
• Skin lesion biopsy

How this condition is treated depends on:

• How much the immune system is suppressed (immunosuppression)
• Number and location of the lesions
• Symptoms

Treatments include:

• Antiviral therapy against the AIDS virus
• Combination chemotherapy
• Freezing (cryotherapy)
• Radiation therapy

Lesions may return after treatment.

Treating Kaposi's sarcoma does not improve the chances of survival from AIDS itself. The outlook depends on the person's immune status and how much of the HIV virus is in the patient's blood (viral load).

Complications can include:

• Cough and shortness of breath (if the disease is in the lungs)
• Leg swelling that may be painful or cause infections (if the disease is in the lymph nodes of the legs)

The tumors can return even after 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 HIV infection. This prevents AIDS and its complications, including Kaposi's sarcoma.

Volberding PA. Hematology and oncology in patients with human immunodeficiency virus infection. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 416.