In contrast, PDHGG is described by diffuse growth, high-grade morphology, and increased mitosis and often shows alterations of histone gene resulting in epigenetic alterations, which contrasts with common isocitrate dehydrogenase (IDH) mutation and epidermal growth factor receptor (EGFR) amplification seen in adult-type high-grade glioma. Here, EGFR is linked to glioma.