[Epithelioid hemangioendothelioma of the mediastinum]

The paper describes a rare case of mediastinal epithelioid hemangioendothelioma characterized by a population of fusiform cells, metaplastic osteogenesis, and aggressive behavior. A 5.5x4-cm encapsulated mass was found in the anterior mediastinum of a 19-year-old female patient. A bone density tumor was sealed with lung tissue and it occluded the lumen of the left subclavian vein. Microscopically, the tumor was composed of foci of the so-called "blister cells" typical of epithelioid hemangioendothelioma, anastomosing chains of epithelioid cells in the microhyaline stroma, diffusely located bone trabeculae, and hemorrhagic stroma. Fusiform cells were present in considerable quantities. A moderate cellular and nuclear polymorphism occurred when mitotic figures were absent. Tumor cells expressed Flil, vimentin, CD31, and CD34. Multiple metastases were detected in the liver and lung. They had the similar morphology.