IDH2 and anaplastic oligoastrocytoma: The WHO 2016 revised diagnosis of the study group was as follows: 10 diffuse astrocytomas - IDH-mutant (11.9%); 3 diffuse astrocytomas- IDH-WT (3.5%); 4 anaplastic astrocytomas- IDH-mutant (4.7%); 23 ODs-IDH-mutant, and 1p/19q codeleted (27.3%); 14 anaplastic ODs, IDH-mutant & 1p/19q-codeleted (16.6%); 1 OD NOS (1.1%); 1 anaplastic oligoastrocytoma (1.1%), and 28 GBM-IDH-WT (33.3%).