Ependymoma arises from ependymal cells lining the central canal of the spinal cord. It represents 60% of spinal cord gliomas, 90% of filum terminale tumors and occurs in adults in 96% of cases (peak age: 30 - 40 yrs). Male:Female = 2:1. The histological type in filum terminale is mixopapillay ependymoma: papillary, with microcystic vacuoles, mucosubstance and connective tissue. No anaplasia, but cerebrospinal fluid dissemination occurs rarely. MR findings are: T1WI - isointense with cord and hyperintensity due to accumulation of mucin; T2WI - almost always hyperintense to cord and hypointensity at tumor margin; STIR - hyperintense; T1 C+ - intense enhancement. Best imaging tools are the sagittal and axial T2WI and T1WI MRI sequences with gadionium. Clinical presentation is with back pain, paraparesis, radiculopathy, sphyncter disturbances. Symptoms present > 1 year prior to diagnosis in 82% of cases. Delay in diagnosis is due to slow tumor growth. Frequently its presentation is with subarachnoid hemorrhage (70% of intradural spine tumors with hemorrhage are ependymomas). The treatment is total resection, gross total resection in > 85% of cases. The filum has characteristic squiggly vessels on its surface, a distinctively whiter appearance than the nerve roots, and ligamenous-like strands. Surgical removal consists of coagulating and dividing the filum terminal just above and below the lesion. Late recurrence and metastases are rare after a complete resection. Radiation therapy is indicated in recurrence or in partial resection.
References
- Handbook of Neurosurgery - fifth edition - Mark S. Greenberg - ed. Thieme.
- Ross JS, Brant-Zawadzki M, Moore KR, et al.. Diagnostic Imaging Spine. First edition - Amirsys - Elsevier Saunders - 2004.
- Sun B et al.. MRI features of intramedullary spinal cord ependymomas. J Neuroimaging 13;(4):346-51,2003.
- Hanbali F et al.. Spinal cord ependymoma: radical surgical resection and outcome. Neurosurgery 51;(5):1162-72.
