Aetiology of Kaposi's sarcoma: current understanding and implications for therapy.

Kaposi's sarcoma is an angiogenic neoplasm composed of endothelial and spindle cells. The enormous increase in Kaposi's sarcoma with HIV infection, and recent discovery that a new human herpesvirus (Kaposi's sarcoma-associated herpesvirus, also called human herpesvirus 8) is present in this tumor, has activated intense interest in the aetiology, epidemiology and pathogenesis of this disease. Today, Kaposi's sarcoma is one of the most frequent neoplasms in men under 50 years old in the USA, and in some African countries it is the most common tumour overall.