title: Morphologic and molecular genetic aspects of oligodendroglial neoplasms.
abstract: Morphologic criteria for diagnosing oligodendrogliomas and for classifying them as well-differentiated (World Health Organization grade II) and anaplastic (World Health Organization grade III) are well recognized. Nevertheless, applying these guidelines to specific cases often reveals discrepancies among different observers. In addition, whether a given tumor also contains an astrocytic component may be debatable. Loss of heterozygosity studies have demonstrated that oligodendroglial neoplasms have a high incidence of loss of the 1p and 19q chromosomal arms. Although loss of heterozygosity for portions of 19q are sometimes seen in astrocytic neoplasms, these tumors seldom show complete loss of 19q accompanied by loss of 1p. Loss of 9p or homozygous deletion of the CDKN2 gene or both are associated with anaplastic oligodendrogliomas, whereas loss of 17p or TP53 gene mutations or both are frequent in astrocytomas, but rare in oligodendrogliomas. These observations suggest that molecular genetic parameters could provide an objective, reproducible framework for classifying oligodendroglial neoplasms.
authors.affiliation: Department of Pathology, Duke University Medical Center, Box 3712, Durham, NC 27710, USA.
authors.forename: S H
authors.initials: SH
authors.lastname: Bigner
authors.forename: B K
authors.initials: BK
authors.lastname: Rasheed
authors.forename: R
authors.initials: R
authors.lastname: Wiltshire
authors.forename: R E
authors.initials: RE
authors.lastname: McLendon
mesh_terms: D001254:Astrocytoma / Q000145:classification / Q000235:genetics / Q000473:pathology; D001932:Brain Neoplasms / Q000145:classification / Q000235:genetics / Q000473:pathology*; D002877:Chromosomes, Human / Q000235:genetics / Q000648:ultrastructure; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000502:physiology; D016147:Genes, Tumor Suppressor; D019942:Genes, p16; D016158:Genes, p53; D005910:Glioma / Q000145:classification / Q000235:genetics / Q000473:pathology; D006801:Humans; D007621:Karyotyping; D019656:Loss of Heterozygosity; D009693:Nucleic Acid Hybridization; D009837:Oligodendroglioma / Q000145:classification / Q000235:genetics / Q000473:pathology*; D016159:Tumor Suppressor Protein p53 / Q000502:physiology; D014944:World Health Organization
chemical_list: D019941:Cyclin-Dependent Kinase Inhibitor p16; D016159:Tumor Suppressor Protein p53