Kaposi's sarcoma is a specific type of cancer that involves the tissues of the skin or the coverings of blood vessels.

What is going on in the body?

Kaposi's sarcoma , or KS, usually begins in certain skin cells. These cells undergo cancerous changes and begin to grow uncontrollably. For people with intact immune systems, the cancer grows slowly, if at all, and rarely spreads. The disease becomes very aggressive if the person has an impaired immune system. HIV infections and drugs given after organ transplant will suppress the immune system. Until AIDS became widespread, KS was rarely seen. KS is common in people with AIDS.

What are the causes and risks of the disease?

People with HIV infection are at very high risk for KS. After organ transplant, people are given powerful drugs to prevent rejection of the new organ. Those people are also at risk. KS is otherwise very rare, but may be seen in a lesser form in elderly men of Mediterranean origin.