Challenge of Diagnostic Criteria for Diffuse Hemispheric Glioma (DHG), H3 G34‐Mutant: A Case of DHG Without H3.3 Gene Alteration

We present a case of diffuse hemispheric glioma (DHG), H3 G34-mutant, NEC. Postoperative histological examination and DNA sequencing detected some features consistent with DHG, H3 G34-mutant; however, no canonical H3 alterations or ATRX variants were detected. The diagnosis could only be established based on the DNA methylation profiling result. In light of these distinctive molecular findings, we propose some insights into the current WHO diagnostic criteria for DHG H3-G34 and emphasise the value of comprehensive molecular diagnosis.