Kaposi's Sarcoma (KS) is a tumor, caused by herpesvirus type-8 (HHV-8), that affects the tissues under the skin, or the mucous membranes that line the mouth, nose, and anus. There are different forms of this vascular tumor.
The classic form of KS generally affects older men of Italian, Jewish, or Eastern European descent. It is slow growing (indolent), relatively painless, and rarely fatal.
An endemic form occurs in Africa, in cycles independent of HIV infections. The adult form is more indolent, like classic KS; while the prepubertal form is more aggressive and often fatal.
AIDS-associated KS is the most common malignancy associated with AIDS and is more aggressive than classic KS, often involving the mucosa, lymph nodes, and GI system. Frequently, these tumors are the first visible symptom of AIDS.