title: A distinct pattern of Olig2-positive cellular distribution in papillary glioneuronal tumors: a manifestation of the oligodendroglial phenotype?
abstract: Mixed neuronal-glial tumors of the central nervous system display a wide spectrum of differentiation. Among them, the papillary glioneuronal tumor (PGNT) is characterized by pseudopapillary structures composed of astroglial cells covering hyalinized vessels, and by neurocytic, ganglioid and ganglion cells. In addition, a "nonspecific" cell type, not similar to either astrocytes or neurocytes, has been recognized since the initial reports. Recently, minigemistocytic cells and a population immunostained by anti-Olig2 antibody have also been recognized in PGNT. Olig2 is a transcription factor that is specific for the cellular phenotype of oligodendrocytes. The aim of this study was to further investigate the histological diversity of PGNT. We examined six cases of PGNT, each of which showed Olig2 immunopositivity. Minigemistocytes were encountered in three cases at close proximity to the Olig2-positive area. Olig2-positive cells were negative for glial fibrillary acidic protein (GFAP) and neuronal nuclear antigen by double immunostaining, and mainly occupied the interpapillary area laterally adjacent to the GFAP-positive cells. They had relatively small, round and vesicular nuclei, and were formerly regarded as neurocytic cells or nonspecific cellular elements. Fluorescence in situ hybridization targeting chromosome 1p failed to demonstrate any deletion. This study disclosed an additional cellular component of PGNT that is characterized by Olig2 positivity, suggestive of oligodendroglial phenotype, and the results also encourage us to investigate oligodendroglial participation in various glioneuronal tumors.
authors.affiliation: Department of Human Pathology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yokoo
authors.forename: Takashi
authors.initials: T
authors.lastname: Komori
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Makita
authors.forename: Takashi
authors.initials: T
authors.lastname: Ishizawa
authors.forename: Takanori
authors.initials: T
authors.lastname: Hirose
authors.forename: Michimasa
authors.initials: M
authors.lastname: Ebato
authors.forename: Junji
authors.initials: J
authors.lastname: Shibahara
authors.forename: Choutatsu
authors.initials: C
authors.lastname: Tsukayama
authors.forename: Makoto
authors.initials: M
authors.lastname: Shibuya
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Nakazato
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001253:Astrocytes / Q000378:metabolism / Q000473:pathology; D051792:Basic Helix-Loop-Helix Proteins; D014408:Biomarkers, Tumor / Q000032:analysis*; D001932:Brain Neoplasms / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D005910:Glioma / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D000076104:Oligodendrocyte Transcription Factor 2
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D014408:Biomarkers, Tumor; D005904:Glial Fibrillary Acidic Protein; D009419:Nerve Tissue Proteins; D000076104:Oligodendrocyte Transcription Factor 2; C405708:OLIG2 protein, human