[Intracranial mesenchymal chondrosarcoma arising from the cerebellar tentorium: case report].

A 22-year-old woman presented with a 3-year history of progressive frontal headache. Computerized tomography (CT) and magnetic resonance imaging (MRI) revealed a tumor in the left trigone of the lateral ventricle and which enhanced homogeneously. The tumor was attached to the cerebellar tentorium and was compressing the brain stem. On the angiography, no tumor staining was seen. On November 26, 1996, total removal of the tumor was performed using the left subtemporal approach. The tumor was attached to the cerebellar tentorium. The pathological diagnosis was mesenchymal chondrosarcoma. After surgery, gamma-knife radiosurgery was carried out on the tentorium at the place where the tumor had been attached. There has been no recurrence for 6 months. Mesenchymal chondrosarcoma in the brain is very rare and therapy for this tumor is difficult. We report this rare tumor and the therapy is discussed.