title: Isocitrate dehydrogenase 1 analysis differentiates gangliogliomas from infiltrative gliomas.
abstract: Recent work has identified novel point mutations in isocitrate dehydrogenase 1 (IDH1) in the majority of the World Health Organization grades II and III infiltrative gliomas and secondary grade IV glioblastomas. Gangliogliomas consist of neoplastic ganglion and glial cells and, in contrast to infiltrative gliomas, are generally indolent. Yet distinguishing between a ganglioglioma and an infiltrative glioma with admixed gray matter can be difficult, perhaps accounting for some "gangliogliomas" that ultimately show aggressive behavior. In this multi-institutional study, 98 cases originally diagnosed as ganglioglioma were analyzed for IDH1 mutations, 86 of which had follow-up data available. Eight cases (8.2%) were positive for R132H IDH1 mutations; six had silent IDH2 mutations and two had nonsense IDH2 mutations. The presence of mutant IDH1 in gangliogliomas correlated with a greater risk of recurrence (P=0.0007) and malignant transformation and/or death (P<0.0001) compared with tumors that were IDH1 wild type. Furthermore, the age of patients with IDH1-mutant gangliogliomas was higher than those without mutations (25.5 vs. 46.1 years, P=0.0033). IDH1/2 testing of tumors suspected of being gangliogliomas may therefore be advisable, particularly in the adult population.
authors.affiliation: Department of Pathology, University of Kentucky, Lexington, KY 40536, USA. craig.horbinski@uky.edu
authors.forename: Craig
authors.initials: C
authors.lastname: Horbinski
authors.forename: Julia
authors.initials: J
authors.lastname: Kofler
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Yeaney
authors.forename: Sandra
authors.initials: S
authors.lastname: Camelo-Piragua
authors.forename: Sriram
authors.initials: S
authors.lastname: Venneti
authors.forename: David N
authors.initials: DN
authors.lastname: Louis
authors.forename: Arie
authors.initials: A
authors.lastname: Perry
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Murdoch
authors.forename: Marina
authors.initials: M
authors.lastname: Nikiforova
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004252:DNA Mutational Analysis; D005260:Female; D018303:Ganglioglioma / Q000235:genetics* / Q000473:pathology; D005910:Glioma / Q000235:genetics* / Q000473:pathology; D006801:Humans; D007223:Infant; D007521:Isocitrate Dehydrogenase / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D012189:Retrospective Studies; D012307:Risk Factors; D013223:Statistics as Topic; D016019:Survival Analysis; D055815:Young Adult
chemical_list: D007521:Isocitrate Dehydrogenase