Thoracic exophytic ependymoma masquerading as a benign extra-axial tumor.

Spinal tumors are conventionally differentiated based on location in relation to the spinal cord. Benign spinal tumors such as schwannomas and meningiomas are typically extra-axial (intradural extramedullary) lesions, whereas more aggressive primary spinal tumors such as ependymomas are typically intramedullary masses. Rarely, ependymomas can have both intramedullary and extramedullary components (typically referred to as exophytic ependymomas). We report a case of a spinal exophytic ependymoma that radiographically masqueraded as a benign intradural extramedullary lesion causing cord compression and neurologic deficit in a 47-year-old man. The diagnosis of exophytic ependymoma was made intra-operatively, with resultant gross total resection of the extramedullary portion and subtotal resection of the intramedullary portion. Histopathological examination confirmed ependymoma with World Health Organization grade II/IV. Pre-operative suspicion of an exophytic ependymoma influences operative planning and clinical management. We review the literature and discuss clinical management strategies for these interesting spinal tumors.