Cauda equina paraganglioma with ependymoma-like histology: a case report.

Paraganglioma affecting the cauda equina region is very rare and can be misinterpreted as an ependymoma which is more common at this site. A 38-year-old woman with a paraganglioma in the cauda equina is presented. MRI revealed a well-circumscribed, intradural, extramedullary tumor nodule with the dimensions of 2.5x1x1 cm. The patient underwent L3 laminectomy and total excision of the tumor. The tumor was diagnosed as ependymoma and the patient was decided to undergo adjuvant radiotherapy. The patient applied to our medical center for a second opinion. Histopathologically, her tumor was found to be a paraganglioma with ependymal features. Therefore no adjuvant therapy was applied. There is no evidence of recurrence or metastases for 15 months after her operation. Paraganglioma in the cauda equina/ filum terminale is very rare and can be misdiagnosed as ependymoma especially when it exhibits ependymoma-like histology. This rare form of paraganglioma behaves like a WHO grade I tumor of CNS like classic paraganglioma. No recurrence or metastasis is expected when it is totally resected. Morphology can be misleading hence immunohistochemistry and/or ultrastructural study is necessary for correct diagnosis.