title: Anaplastic ependymoma with ependymoblastic multilayered rosettes.
abstract: Anaplastic ependymoma, World Health Organization grade III, is a malignant glioma with ependymal differentiation characterized by high mitotic activity often accompanied by microvascular proliferation and necrosis, where, generally, much fewer ependymal rosettes are found than in ependymoma, World Health Organization grade II. Ependymal rosettes, forming a single layer of tumor cells, differ from ependymoblastic multilayered rosettes, which are characteristic histologic features of ependymoblastoma, a variant of central nervous system primitive neuroectodermal tumor. Here, we report an autopsy case involving a 24-year-old woman with a frontal lobe tumor, which showed the aggregation of true rosettes with multilayering of tumor cells resembling the ependymoblastoma histology. Molecular and cytogenetic analyses revealed the absence of 19q13.42 amplification, a specific molecular hallmark of ependymoblastoma and embryonal tumor with abundant neuropil and true rosettes, supporting the diagnosis of anaplastic ependymoma.
authors.affiliation: Department of Human Pathology, Gunma University Graduate School of Medicine, Gunma 371-8511, Japan. Electronic address: nobusawa@showa.gunma-u.ac.jp.
authors.forename: Sumihito
authors.initials: S
authors.lastname: Nobusawa
authors.forename: Aya
authors.initials: A
authors.lastname: Suzuki
authors.forename: Masaya
authors.initials: M
authors.lastname: Nagaishi
authors.forename: Koji
authors.initials: K
authors.lastname: Isoda
authors.forename: Hayato
authors.initials: H
authors.lastname: Ikota
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yokoo
authors.forename: Junko
authors.initials: J
authors.lastname: Hirato
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Nakazato
mesh_terms: D001344:Autopsy; D001932:Brain Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics; D020732:Cytogenetic Analysis; D003937:Diagnosis, Differential; D004806:Ependymoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D017809:Fatal Outcome; D005260:Female; D005625:Frontal Lobe / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D018242:Neuroectodermal Tumors, Primitive / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D019581:Neuropil / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D055815:Young Adult
keywords: 19q13.42; Ependymoblastic rosettes; Ependymoma