Mystery case: tanycytic ependymoma of the conus medullaris: a rare cause of low back pain.

A 25-year-old woman presented to the emergency department with low back pain radiating to the anterior aspect of both thighs, progressively worsening over 6 months. Her neurologic examination was unremarkable. MRI of the lumbar spine revealed an intradural extramedullary lesion located in the region of the conus medullaris (figure 1, A–D). The patient underwent bilateral T12 and L1 laminectomies and partial bilateral T11 laminectomy for resection of the intradural extramedullary tumor arising from the filum terminale. Her postoperative period was uneventful. The tumor’s location and imaging characteristics were suggestive of a myxopapillary ependymoma. However, histopathologic workup ultimately rendered the diagnosis of tanycytic ependymoma, a rare occurrence at this site (figure 2, A–D). This must be differentiated from schwannoma and astrocytoma due to therapeutic and prognostic implications. AUTHOR CONTRIBUTIONS Dr. Furlan was responsible for design and conceptualization of the study, analysis and interpretation of the data, draft and revisions of the manuscript. Dr. Chui was responsible for design and conceptualization of the study, analysis and interpretation of the data, draft and revisions of the manuscript. Dr. Croul was responsible for design and conceptualization of the study, analysis and interpretation of the data, draft and revisions of the manuscript. Dr. Paul Kongkham was responsible for design and conceptualization of the study, analysis of the data, draft and revisions of the manuscript.