title: A case of anaplastic clear-cell ependymoma presenting with high erythropoietin concentration and 1p/19q deletions.
abstract: We describe a 19-year-old woman with onset of epileptic seizure, and a small mural nodule and multicystic lesions with severe brain edema located in the right frontal lobe. At surgery, the tumor and a clear margin was removed, and symptoms improved postoperatively. Extended local radiotherapy (60 Gy) was performed. Histopathological examination revealed oligodendroglioma-like tumor cells with a perinuclear halo. The tumor cells extended processes toward CD34-positive proliferating vessels, which resemble a basement membrane. These proliferating vessels formed a tumor membrane so that there was a clear margin between the tumor and brain tissue. Tumor cells were positive for epithelial membrane antigen in a dot-like pattern. MIB-1 staining index was 50.6%. Electron microscopy showed cilia and zipper-like junctions, and anaplastic clear-cell ependymoma grade III was diagnosed. A characteristic of the case was formation of a tumor membrane by proliferating tumor blood vessels. Fluorescence in situ hybridization showed 1p/19q deletions, and the concentration of erythropoietin in the cyst fluid was abnormally high, at 1,859.4 mIU/ml. Erythropoietin and erythropoietin receptors were verified with immunohistochemical staining.
authors.affiliation: Department of Neurosurgery, Hirosaki University Graduate School of Medicine, Zaifu-cho 5, Hirosaki, Aomori 036-8562, Japan. asanoken@cc.hirosaki-u.ac.jp
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Asano
authors.forename: Kanae
authors.initials: K
authors.lastname: Kudo
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Mori
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ohkuma
authors.forename: Koichi
authors.initials: K
authors.lastname: Wakabayashi
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology*; D002872:Chromosome Deletion; D002878:Chromosomes, Human, Pair 1; D002888:Chromosomes, Human, Pair 19; D004806:Ependymoma / Q000737:chemistry / Q000235:genetics / Q000473:pathology*; D004921:Erythropoietin / Q000032:analysis*; D005260:Female; D006801:Humans
chemical_list: D004921:Erythropoietin