Primary brain sarcomas: light and electron microscopic features.

The following is a description of the diagnostic structural features in three neoplasms in which we diagnosed: primary intraparenchymal brain sarcoma. One appeared to have arisen de novo from the mesenchymal components of the brain parenchyma and was labeled fibrosarcoma. A second case, having mixed features of meningioma and fibrosarcoma, may represent an instance of sarcomatous changes in a prexisting intraparenchymal meningioma. The third sarcoma's ultrastructural characteristics were those of embryonal capillaries and a designation of hemangiosarcoma is proposed for that one. An angiographic, preoperative diagnosis of meningioma was suggested in all three instances. Two of the patients died a few weeks after craniotomy and the third one is alive and well eighteen months after resection of the neoplasm.