title: Clear-cell ependymoma of the cerebellum: a case report.
abstract: A case of clear-cell ependymoma occurring in the cerebellum of a 3-year-old girl is reported. Light-microscopically, the tumor consisted mainly of clear cells with a perinuclear halo and showed some vague perivascular pseudorosettes, not true rosettes. In addition, the histological features of anaplasia, characterized by increased mitosis and focal pseudopalisading necrosis, were also observed. Immunohistochemically, the tumor cells were focally positive for glial fibrillary acidic protein and weakly positive for epithelial membrane antigen. Ultrastructurally, the intermediate junctions and rudimentary cilia confirmed the ependymal differentiation. Fifteen cases of infratentorial clear-cell ependymoma have been reported to date, and this case is the second childhood tumor among them, to the best of the authors' knowledge.
authors.affiliation: Department of Pathology, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Kim
authors.forename: Byung-Kyu
authors.initials: BK
authors.lastname: Cho
authors.forename: In-One
authors.initials: IO
authors.lastname: Kim
authors.forename: Sung-Hye
authors.initials: SH
authors.lastname: Park
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D002528:Cerebellar Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000628:therapy; D002675:Child, Preschool; D003131:Combined Modality Therapy; D004806:Ependymoma / Q000737:chemistry / Q000473:pathology* / Q000628:therapy; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D006003:Glycogen / Q000648:ultrastructure; D006801:Humans; D007382:Intermediate Filaments / Q000648:ultrastructure; D008279:Magnetic Resonance Imaging; D046529:Microscopy, Electron, Transmission; D018396:Mucin-1 / Q000032:analysis; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D005904:Glial Fibrillary Acidic Protein; D018396:Mucin-1; D006003:Glycogen