This case shows a progression over 6 years from a grade 2 to a grade 4 lesion, with an enhancing focus with necrosis and microvascular proliferation confirmed on pathology. Prior to the 2021 WHO CNS 5th edition update, this would have been termed a glioblastoma IDH mutant (or in even older terminology a secondary glioblastoma), but now due to this mutation it should be termed a diffuse astrocytoma, IDH mutant, WHO CNS grade 4.