title: Nogo-A: a useful marker for the diagnosis of oligodendroglioma and for identifying 1p19q codeletion.
abstract: The differential diagnosis between oligodendrogliomas and other gliomas remains a critical issue. The aim of this study is to verify the diagnostic value of Olig-2, Nogo-A, and synaptophysin and their role in identifying 1p19q codeletion. A total of 168 cases of brain tumors were studied: 24 oligodendrogliomas, 23 anaplastic oligodendrogliomas, 2 oligoastrocytomas, 2 anaplastic oligoastrocytomas, 30 glioblastoma multiforme, 2 diffuse astrocytomas, 4 anaplastic astrocytomas, 10 pilocytic astrocytomas, 9 ependymomas, 12 anaplastic ependymomas, 10 central neurocytomas, 10 meningiomas, 10 choroid plexus papillomas, 10 dysembryoplastic neuroepithelial tumors, and 10 metastases. All cases were immunostained with Olig-2, Nogo-A, and synaptophysin. In 79 cases, the status of 1p/19q had already been assessed by fluorescence in situ hybridization. Thus, in selected cases, fluorescence in situ hybridization was repeated in areas with numerous Nogo-A-positive neoplastic cells. Nogo-A was positive in 18 (75%) of 24 oligodendrogliomas, 8 (80%) of 10 dysembryoplastic neuroepithelial tumors, 6 (20%) of 30 glioblastoma multiforme, and 2 (20%) of 10 pilocytic astrocytomas. Olig-2 stained 22 (91.6%) of 24 oligodendrogliomas and all dysembryoplastic neuroepithelial tumors but also 24 (80%) of 30 glioblastoma multiforme and 8 (80%) of 10 pilocytic astrocytomas. Finally, synaptophysin stained 13 (54.1%) of 24 oligodendrogliomas, 3 (10%) of 30 glioblastoma multiforme, 1 (10%) of 10 pilocytic astrocytomas, and all neurocytomas. Among the 79 tested cases, original fluorescence in situ hybridization showed 1p/19q codeletion in 12 (52.2%) of 23 oligodendrogliomas, 8 (38%) of 21 anaplastic oligodendrogliomas, and 1 (4%) of 25 glioblastoma multiforme. However, after carrying out the Nogo-A-driven fluorescence in situ hybridization, 1p/19q codeletion was observed in 8 additional cases. Nogo-A is more useful and specific than Olig-2 in differentiating oligodendrogliomas from other gliomas. Furthermore, using a Nogo-A-driven fluorescence in situ hybridization analysis, it is possible to identify a larger number of 1p19q codeletions in gliomas.
authors.affiliation: Section of Pathology M. Malpighi, Department of Haematology and Oncological Sciences L. and A. Seragnoli, Bellaria Hospital, University of Bologna, 40139 Bologna, Italy. gianluca.marucci@ausl.bologna.it
authors.forename: Gianluca
authors.initials: G
authors.lastname: Marucci
authors.forename: Enrico
authors.initials: E
authors.lastname: Di Oto
authors.forename: Anna
authors.initials: A
authors.lastname: Farnedi
authors.forename: Riccardo
authors.initials: R
authors.lastname: Panzacchi
authors.forename: Claudia
authors.initials: C
authors.lastname: Ligorio
authors.forename: Maria P
authors.initials: MP
authors.lastname: Foschini
mesh_terms: D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D001932:Brain Neoplasms / Q000235:genetics / Q000378:metabolism / Q000556:secondary*; D002878:Chromosomes, Human, Pair 1; D002888:Chromosomes, Human, Pair 19; D003937:Diagnosis, Differential; D005260:Female; D017353:Gene Deletion; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D009185:Myelin Proteins / Q000235:genetics / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D000070798:Nogo Proteins; D000076104:Oligodendrocyte Transcription Factor 2; D009837:Oligodendroglioma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D011237:Predictive Value of Tests; D016708:Synaptophysin / Q000235:genetics / Q000378:metabolism
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D014408:Biomarkers, Tumor; D009185:Myelin Proteins; D009419:Nerve Tissue Proteins; D000070798:Nogo Proteins; D000076104:Oligodendrocyte Transcription Factor 2; D016708:Synaptophysin; C405708:OLIG2 protein, human; C000603199:RTN4 protein, human