title: Olig2-positive cells in glioneuronal tumors show both glial and neuronal characters: the implication of a common progenitor cell?
abstract: Glioneuronal tumors (GNTs) are rare neoplasms consisting of both glial and neuronal components. Among the GNTs, dysembryoplastic neuroepithelial tumors (DNTs), papillary glioneuronal tumors (PGNTs), and rosette-forming glioneuronal tumors of the fourth ventricle (RGNTs) share the character of being mainly composed of small round Olig2-positive tumor cells. Using immunohistochemistry and fluorescence in situ hybridization, we examined a series of 35 GNT cases (11 DNTs, 15 PGNTs and 9 RGNTs) on the characteristics of Olig2-positive tumor cells. Histologically, Olig2-positive cells showed small round forms in most GNTs; however, there were a small number of Olig2-positive cells with neuronal morphology only in a PGNT case. These cells expressed both glial and neuronal markers by double immunostaining. With regard to labeling indices and intensity, only PGNT cells expressed neuronal markers, including α-internexin and neurofilament. These findings also suggest that some Olig2-positive PGNT cells may show neuronal differentiation. In GNTs, a considerable number of Olig2-positive cells showed immunopositivity for cyclin D1 and/or platelet-derived growth factor receptor alpha (PDGFRα), which are markers for oligodendrocyte progenitor cells. These immunostainings were particularly strong in DNTs. In RGNTs, Olig2-positive cells formed "neurocytic rosettes". Furthermore, they were also immunopositive for glial markers, including GFAP, PDGFRα and cyclin D1. These findings indicate the heterogeneous characteristics of Olig2-positive cells in GNTs, and some of them also exhibited neuronal features. So it is possible that a part of Olig2-positive GNT cells have characteristics similar to those of progenitor cells.
authors.affiliation: Department of Human Pathology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan. nozomim@med.gunma-u.ac.jp
authors.forename: Nozomi
authors.initials: N
authors.lastname: Matsumura
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yokoo
authors.forename: Ying
authors.initials: Y
authors.lastname: Mao
authors.forename: Wang
authors.initials: W
authors.lastname: Yin
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Nakazato
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics*; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology / Q000648:ultrastructure; D002648:Child; D002675:Child, Preschool; D005260:Female; D005910:Glioma / Q000235:genetics* / Q000473:pathology / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009457:Neuroglia / Q000473:pathology*; D009474:Neurons / Q000473:pathology*; D000076104:Oligodendrocyte Transcription Factor 2; D009836:Oligodendroglia / Q000473:pathology; D012397:Rosette Formation; D013234:Stem Cells / Q000473:pathology*; D055815:Young Adult
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D009419:Nerve Tissue Proteins; D000076104:Oligodendrocyte Transcription Factor 2; C405708:OLIG2 protein, human