Kaposi's sarcoma

Definition:

A malignant tumor frequently involving the skin in persons with AIDS.

Causes, incidence, and risk factors:

Before the AIDS epidemic, Kaposi's sarcoma was seen primarily in elderly Italian and Jewish men and developed slowly in these people. In AIDS patients, it can develop aggressively and often involves the skin, lungs, gastrointestinal tract and other organs. In AIDS, the disease may be caused by immune suppression and recent research suggests that it is a combination of suppression and an as yet unidentified type of herpes virus. The tumors consist of bluish-red or purple nodules made up of vascular tissue. Early lesions may start on the feet or ankles, and spread to the arms and hands. The incidence is approximately 3 out of 100,000 people.