Kaposi's sarcoma -- Case report and review of Japanese cases.

A case of Kaposi's sarcoma in a 60 year-old male was examined histologically and electron microscopically. Multiple hemorrhagic skin lesions were confined within the scalp. The major part of initial skin biopsies exhibited capillary hemangiomatous component, but examination of surgical materials confirmed its nature as hemorrhagic sarcoma. At autopsy, the skin lesions showed various histological pictures ranging from angiomatous or granulomatous to sarcomatous proliferation of spindle-shaped cells. Of intriguing findings were the bone marrow involvement and the pulmonary changes, the former consisting of typical sarcomatous lesion and the latter being characterized by purpuric appearance of the pleura responsible for the terminal pneumohemothorax. Electron microscopically, the tumor cells showed Weibel-Palade granules in the cytoplasm suggesting the endothelial nature. In this article, Japanese autopsy cases of Kaposi's sarcoma so far reported are summarized.