Subependymoma of the septum pellucidum radiologically indistinguishable from cavernous angioma--case report.

A case of subependymoma of the septum pellucidum in a 54-year-old female is presented. Computed tomography and magnetic resonance imaging revealed a partially calcified mass with intratumoral hematomas, and cerebral angiograms disclosed a relatively hypovascular lesion. Preoperatively, a cavernous angioma was suspected. The tumor was removed, and histological examination proved it to be a subependymoma containing a fine fibrillary matrix. On immunohistochemical analysis, both the matrix and the tumor cells were positive for glial fibrillary acidic protein staining.