Thoracic Intradural Extramedullary Ependymoma with Anaplastic Transformation: Case Report and Discussion.

Background: Intradural extramedullary spinal ependymomas arising from outside the region of the conus medullaris are rare clinical entities, and anaplastic transformation of these lesions is even more exceptional.

Methods: We report on a case of an intradural extramedullary T5-T6 ependymoma that underwent gross total resection. Histologic analysis of the initial tumor revealed a World Health Organization grade 2 ependymoma. Two years after initial surgical resection, there was radiologic recurrence and a re-do resection was performed with subsequent spinal stabilization. Histologic analysis of the recurrent tumor revealed a World Health Organization grade 3 ependymoma. After surgery the patient received radiotherapy, and he remains disease free at 2 years following his second surgery. In addition, we employed carbon fiber screws and rods for stabilization in his second operation to reduce artefact on follow-up imaging.

Conclusions: We advocate that primary spinal ependymomas should be within the differential of intradural extramedullary lesions arising outside the region of the conus medullaris.