Kaposi Sarcoma
The lesions can occur anywhere on skin or mucous membranes as well as in internal organs. Cutaneous lesions are usually nonpruritic. They can be macular, papular, or plaque-like and brown, pink, red, or purple. Biopsy is required for diagnosis. Differential diagnosis includes bacillary angiomatosis and pyogenic granuloma.
A diagnostic lesion is composed of plump spindle cells with slit-like vascular spaces and/or extravasated RBCs. AIDS-associated KS occurs in ~33% of AIDS patients, usually homosexual males. Lesions can occur in any location. 33% develop lymphoma but most die of other AIDS manifestations. Human herpesvirus 8 is found in 95% of KS lesions, in both endemic and epidemic forms of the disease.