– A malignant vascular tumor of the endothelium that originates in multifocal sites. (Also see AIDS.)
Causes and Incidence
The etiology is unknown, but cytomegalovirus (CMV) is a suspected cause. At one time the incidence of Kaposi’s sarcoma (KS) was confined to a select population of older men of Jewish or Italian origin and to those who were severely immunocompromised. In late 1980, however, an alarming increase in cases occurred among sexually active, homosexual men between 25 and 50 years of age. KS is currently the most common AIDS-related cancer, occurring in at least one third of those diagnosed with AIDS in the United States. It is endemic in equatorial Africa and accounts for more than 10% of malignancies in Zaire and Uganda.
KS lesions begin in the endothelial cells, which originate in the middermis, oral mucosa, lymph nodes, and gastrointestinal viscera. The lesions spread to the skin, lungs, liver, and bones. Skin lesions are typically reddish brown or purple and are various shapes and sizes.
Individuals can have varying degrees of cutaneous and systemic involvement. The presenting signs are usually multiple skin and oral mucosal lesions that are small, round, and pink and progress to red or purple. Later symptoms indicate systemic disease and include diarrhea, weight loss, cough, dyspnea, and fever.
Associated opportunistic infections and the immunosuppression associated with AIDS complicate the course and treatment of KS.
The initial diagnosis is made from the presence of the characteristic lesions and a history of AIDS or Jewish or Italian heritage. The definitive diagnosis is made by biopsy of the skin lesions.
Excision or electrodesiccation of skin lesions.
Combination chemotherapy for progressive or widespread disease.
Irradiation of skin lesions and as palliation.