title: Glioblastomas with oligodendroglial component-common origin of the different histological parts and genetic subclassification.
abstract: BACKGROUND
  Glioblastomas are the most common and most malignant brain tumors in adults. A small subgroup of glioblastomas contains areas with histological features of oligodendroglial differentiation (GBMO). Our objective was to genetically characterize the oligodendroglial and the astrocytic parts of GBMOs and correlate morphologic and genetic features with clinical data.
  
  
  METHODS
  The oligodendroglial and the "classic" glioblastoma parts of 13 GBMO were analyzed separately by interphase fluoreszence in situ hybridization (FISH) on paraffin sections using a custom probe set (regions 1p, 1q, 7q, 10q, 17p, 19q, cen18, 21q) and by comparative genomic hybridization (CGH) of microdissected paraffin embedded tumor tissue.
  
  
  RESULTS
  We identified four distinct genetic subtypes in 13 GBMOs: an "astrocytic" subtype (9/13) characterized by +7/-10; an "oligodendroglial" subtype with -1p/-19q (1/13); an "intermediate" subtype showing +7/-1p (1/13), and an "other" subtype having none of the former aberrations typical for gliomas (2/13). The different histological tumor parts of GBMO revealed common genetic changes in all tumors and showed additional aberrations specific for each part.
  
  
  CONCLUSIONS
  Our findings demonstrate the monoclonal origin of GBMO followed by the development of the astrocytic and oligodendroglial components. The diagnostic determination of the genetic signatures may allow for a better prognostication of the patients.
authors.affiliation: Institut für Klinische Genetik, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Germany. barbara.klink@tu-dresden.de
authors.forename: Barbara
authors.initials: B
authors.lastname: Klink
authors.forename: Ben
authors.initials: B
authors.lastname: Schlingelhof
authors.forename: Martin
authors.initials: M
authors.lastname: Klink
authors.forename: Karen
authors.initials: K
authors.lastname: Stout-Weider
authors.forename: Stephan
authors.initials: S
authors.lastname: Patt
authors.forename: Evelin
authors.initials: E
authors.lastname: Schrock
mesh_terms: D000328:Adult; D000368:Aged; D001253:Astrocytes / Q000378:metabolism / Q000473:pathology; D002877:Chromosomes, Human / Q000235:genetics; D055028:Comparative Genomic Hybridization; D005260:Female; D005909:Glioblastoma / Q000145:classification / Q000235:genetics* / Q000473:pathology* / Q000532:radiotherapy; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007399:Interphase; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009836:Oligodendroglia / Q000378:metabolism* / Q000473:pathology*; D016019:Survival Analysis