Extramedullary spinal ependymoma: a diagnostic challenge and review of the literature.

Of the 15 cases of intradural extramedullary ependymomas in the literature, only 3 patients were male. The authors report the fourth case to be diagnosed in a male patient and discuss the pathogenesis, presentation, and treatment of this rare form of ependymoma. These cases most commonly show a similar clinical preoperative course to that of a benign meningioma. Although most instances have been reported in females, hormonal influence may not completely explain this neoplasm's pathogenesis. Close follow-up is warranted because of potential recurrence, metastasis, and anaplastic transformation. An ependymoma should be included in the differential diagnosis of intradural extramedullary tumors.