||The lesions of Kaposi's sarcoma in AIDS patients are unlike the classical Kaposi's sarcoma. The disease runs a shorter course and death is due to widespread dissemination or to opportunistic infection. The tumors tend to be multiple, widespread and may involve most skin surfaces of the body; there is early lymph node involvement and spread to the viscera. The early lesions are quite small, scarcely raised above the skin surface, and tend to be reddish-brown or purple in color, sometimes resembling a bruise. The later lesions are tumid and firm, and tumors on the trunk are often elongated, with the long axis parallel to skin cleavage lines.
Biopsy of the lesions frequently shows a lymphangiomalike pattern, with a few dilated irregular thin-wall capillaries in the dermis, associated with a sparse chronic inflammatory cell infiltrate and a deposition of hemosiderin.
The purplish-red nodule arising on the lateral surface of this patient's pinna was a Kaposi's sarcoma.