Tanycytic ependymoma in association with neurofibromatosis type 2.

A rare case of tanycytic ependymoma associated with neurofibromatosis type 2 (NF2) is presented for the first time, with emphasis on its clinical course and histopathological features. A 30-year-old man had developed gait disturbance in his childhood, and harbored multiple tumors in spinal nerve roots, in the intradural extramedullary and intramedullary spinal cord. The spinal root tumor and intradural extramedullary tumor were histologically diagnosed as schwannoma and meningioma, respectively. Magnetic resonance imaging showed two intramedullary cystic lesions, one in the cervical and the other in the thoracic spine. Because his sensorimotor dysfunction in the lower extremities continued to worsen gradually, three of the multiple nodular tumors in the thoracic cystic lesion were removed. All three tumors were composed of eosinophilic piloid cells with modest nuclear pleomorphism. No Rosenthal fibers were found. A concentration of slender eosinophilic cellular processes surrounding the vascular wall was seen. Periodic acid Schiff and Masson trichrome-positive balloons were seen in the extracellular space. Detection of ependymal rosettes, although only few in number, led the diagnosis as a tanycytic ependymoma. Recognition of this ependymoma variant should be emphasized to avoid confusion with pilocytic astrocytoma or intramedullary schwannoma.