[A case of primary intracranial malignant fibrous histiocytoma associated with peritumoral hemorrhage].

Malignant fibrous histiocytoma (MFH) is common among the soft-tissue sarcoma and especially occurs in the retroperitoneum and the four extremities. However primary intracranial MFH is an extremely rare occurrence. A case with primary intracranial MFH associated with peritumoral hemorrhage is reported. A 81-year-old woman was admitted to our department with impaired consciousness and left hemiparesis. On admission, she was drowsy. Computed tomography (CT) scans revealed a low density mass lesion of 4.5 x 3.5 x 6.0cm in diameter, which was surrounded by a high density area suggesting hematoma, in the right frontal lobe adjacent to the falx cerebri. The low density mass was homogeneously enhanced by contrast medium. Magnetic resonance imaging revealed that the mass was hypointense on T1 weighted image and hyperintense on T2 weighted image. After administration of Gd-DTPA, the mass was homogeneously enhanced and the falx cerebri was also enhanced at the site of attachment. Right carotid angiogram showed a tumor stain fed by the anterior cerebral artery. On operation, bleeding was encountered between the tumor and the falx cerebri on opening the dura mater. Hematoma existed between the tumor and the normal cerebral parenchyma. The tumor was sharply demarcated and didn't invade the normal cerebral parenchyma or the falx cerebri, so we considered that the tumor originated from the meninges. Histologically, pleomorphic spindle cells in atypical storiform pattern were observed. Multinucleated giant cells were also seen. This case suggested to us that primary intracranial MFH may be associated with intracranial hemorrhage.