Currently, according to the WHO classification, diagnosis of oligodendrogliomas requires demonstration of IDH mutation by IDH1 (R132H) immunohistochemistry and/or sequencing of the IDH1/ IDH2 gene, as well as demonstration of 1p/19q codeletion by FISH, chromogenic in situ hybridization, or molecular genetic testing [1]. This evidence concerns the gene IDH1 and oligodendroglioma.