[An autopsy case of primary lung leiomyosarcoma].

We report autopsy findings for a case of leiomyosarcoma originating in the right lung in an 86-year-old man. We surveyed current literatures and compared the immunohistochemical results in the present case with those reported previously in Japan. The solid tumor measured 6 x 7 x 7 cm sized and was located in the right lung. Its cut-surface appeared grayish to yellowish and contained areas of hemorrhage and necrosis. The lungs contained scattered nodular lesions less than 2 cm in diameter. Metastatic lesions were also confirmed in other tissues such as the heart, pericardium, liver, spleen, left adrenal gland and thyroid. Microscopically, 14 mitoses were detected in every 10 high-power fields. An immunohistochemical study revealed positivity for smooth muscle myosin and actin, and negativity for CEA, and appeared to be important in differential diagnosis and determination of histogenetic type.