IDH1 and oligodendroglioma: Diagnosis was IDHwt glioblastoma CNS WHO grade 4 in 70 patients (81%); IDH-mutant (IDHmut) astrocytoma CNS WHO grade 4 in 3 patients (4%), IDHmut astrocytoma CNS WHO grade 3 in 3 patients (4%), IDHmut astrocytoma CNS WHO grade 2 in 4 patients (5%) and oligodendroglioma CNS WHO grade 2 with 1p/19q-codeletion in 6 patients (7%).