Spinal tanycytic ependymomas

Three cases of spinal tanycytic ependymoma are reported, a man aged 45 year s and two women aged 36 and 55 years. Each patient developed gradual parapa resis over a few months prior to admission. Magnetic resonance imaging show ed an enhancing, well-circumscribed tumor in the spinal cord in each case. Histologically, the tumors consisted of monotonous proliferation of long sp indle cells with markedly eosinophilic cell processes; focally forming peri vascular pseudorosettes. The tumor cells were strongly immunopositive for g lial fibrillary acidic protein, S-100 protein and vimentin. Ultrastructural ly, in addition to massive intermediate filaments, many tumor cells showed abundant microtubules. Well-developed desmosomes and microvilli/cilia-lined microlumina were occasionally observed. The tumors were grossly totally re moved and the patients remain recurrence free at 9, 9, and 2 years postoper atively. Reviewing reported cases including our three cases, tanycytic epen dymoma may occur frequently in spinal cord, especially in the cervical regi on of the spinal cord. Since histologically it resembles pilocytic astrocyt oma and schwannoma, tanycytic ependymoma should be included in the differen tial diagnosis of benign spindle cell tumors of the central nervous system.