IDH1 and primitive neuroectodermal tumor: Actually, in a young adult presenting with an IDH-wildtype hemispheric PNET-like tumor, the most likely diagnosis is a diffuse hemispheric glioma, H3 G34-mutant since other entities that can present as PNET-like tumors occur in younger patients.28 Importantly, in the present series, despite the young age of the patients and a high rate of MGMT promoter methylation, adult diffuse hemispheric gliomas, H3 G34-mutant had a poor prognosis.