title: Pilomyxoid astrocytoma of the fourth ventricle in an adult.
abstract: Pilomyxoid astrocytomas have been identified as a variant of pilocytic astrocytoma. They are listed as a novel clinico-pathological entity in the 2007 World Health Organisation (WHO) classification of tumours of the central nervous system. This tumour corresponds to a WHO grade II neoplasm whereas pilocytic astrocytoma corresponds to WHO grade I. We have encountered an infratentorial tumour with pilomyxoid features in an adult. A 25 year old man presented with tinnitus and hyperacusis. Brain MRI revealed a mass occupying the fourth ventricle. We performed partial resection, but no adjuvant therapy was given. The staining index for the anti-Ki-67 monoclonal antibody MIB-1 was less than 1% in this patient. Pilomyxoid astrocytomas are not limited to the hypothalamic/chiasmatic region in children. Additional knowledge and recognition of this entity is necessary to improve treatment of pilomyxoid astrocytoma.
authors.affiliation: Department of Neurosurgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Omura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nawashiro
authors.forename: Hideo
authors.initials: H
authors.lastname: Osada
authors.forename: Katsuji
authors.initials: K
authors.lastname: Shima
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Tsuda
authors.forename: Aida
authors.initials: A
authors.lastname: Shinsuke
mesh_terms: D000328:Adult; D017677:Age Distribution; D001254:Astrocytoma / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D014408:Biomarkers, Tumor / Q000032:analysis / Q000378:metabolism; D002551:Cerebral Ventricle Neoplasms / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D003389:Cranial Nerve Diseases / Q000209:etiology / Q000503:physiopathology; D020546:Fourth Ventricle / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D012001:Hyperacusis / Q000209:etiology; D008279:Magnetic Resonance Imaging; D008297:Male; D019635:Neurosurgical Procedures; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology; D014012:Tinnitus / Q000209:etiology; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor