title: Cerebral and spinal cord tanycytic ependymomas in a young adult with a mutation in the NF2 gene.
abstract: We studied one frontal lobe tumor and multiple spinal cord tumors (one in an extramedullary location) that had been resected from a 24-year-old man. The frontal lobe tumor was well demarcated and non-infiltrating, and consisted of eosinophilic, elongated fibrillary cells arranged in a fascicular pattern. A similar histology was reproduced in the spinal cord tumors, with additional areas showing standard features of ependymoma. Immunohistochemical and ultrastructural observations revealed that all the tumors were ependymal in nature with positivity for GFAP and epithelial membrane antigen and negativity for oligodendrocyte transcription factor 2, showing intra- and intercellular microrosettes, leading us to a diagnosis of tanycytic ependymoma for the frontal lobe tumor and tanycytic ependymoma with ordinary ependymomatous component for the spinal cord tumors. The spinal extramedullary tumor was a schwannoma. Importantly, a heterozygous truncating mutation in the NF2 gene was identified in the blood lymphocytes from the patient. It is known that multiple nervous system tumors can occur in neurofibromatosis type 2 (NF2), which is caused by mutation in the NF2 gene, and that occurrence of ependymoma, including the tanycytic variant, can be associated with this genetic condition. The present case provides further information about the clinicopathology of tanycytic ependymoma with details of the immunohistochemical, ultrastructural and genetic features.
authors.affiliation: Department of Neurosurgery, Ohnishi Neurological Center, Akashi, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kuga
authors.forename: Hideki
authors.initials: H
authors.lastname: Ohnishi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kodama
authors.forename: Shuji
authors.initials: S
authors.lastname: Takakura
authors.forename: Masato
authors.initials: M
authors.lastname: Hayashi
authors.forename: Ryokichi
authors.initials: R
authors.lastname: Yagi
authors.forename: Kenji
authors.initials: K
authors.lastname: Fukutome
authors.forename: Ken
authors.initials: K
authors.lastname: Matsushima
authors.forename: Kouichirou
authors.initials: K
authors.lastname: Okamoto
authors.forename: Katsushi
authors.initials: K
authors.lastname: Taomoto
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D001932:Brain Neoplasms / Q000648:ultrastructure*; D004806:Ependymoma / Q000235:genetics / Q000648:ultrastructure*; D005625:Frontal Lobe / Q000648:ultrastructure*; D006801:Humans; D008297:Male; D009154:Mutation; D025581:Neurofibromin 2 / Q000235:genetics; D013120:Spinal Cord Neoplasms / Q000648:ultrastructure*; D055815:Young Adult
chemical_list: D025581:Neurofibromin 2
keywords: gene analysis; immunohistochemistry; neurofibromatosis type 2 (NF2); tanycytic ependymoma; ultrastructure