[Pulmonary epithelioid hemangioendothelioma]

A 62-year-old asymptomatic woman was referred to the National Cancer Center Hospital in Japan because of an abnormal shadow on an annual checkup chest X-ray. Chest computed tomography(CT)showed a well-demarcated nodular lesion of 3 cm in diameter in the right lower lobe. Since the nodule was located at the right pulmonary hilum, she underwent a right lower lobectomy. Histologically, the tumor was composed of solid nests or anastomosing strands of cells that were embedded in a hyalinized, focally myxoid stroma. Some of the tumor cells showed a striking feature of the presence of intracytoplasmic lumina that were visualized as clear spaces or vacuoles. These lumina were negative for alcian blue and periodic Schiff, and contained erythrocytes. Immunohistochemically, the tumor cells were stained for CD31 and FLI1. The tumor was diagnosed as a pulmonary epithelioid hemangioendothelioma.Pulmonary epithelioid hemangioendothelioma is a relatively rare entity.