Table 1.

The placement of GBM in the WHO Classification of Tumors of the Central Nervous System, fifth edition, 2021 [11].

2021 WHO Classification. Group 1. Gliomas, Glioneuronal Tumors, and Neuronal Tumors
Subgroup	Adult-type diffuse gliomas	Pediatric-type diffuse low-grade gliomas	Pediatric-type diffuse high-grade gliomas	Circumscribed astrocytic gliomas	Glioneuronal and neuronal tumors	Ependymal tumors
Examples	Astrocytoma, IDH-mutant Oligodendroglioma, IDH-mutant and 1p/19q-codeleted GLIOBLASTOMA, IDH-wt	Diffuse astrocytoma, MYB- or MYBL1-altered Angiocentric glioma	Diffuse midline glioma, H3 K27-altered Diffuse hemispheric glioma, H3 G34-mutant	Pilocytic astrocytoma Chordoid glioma Astroblastoma, MN1-altered	Ganglioglioma Gangliocytoma Central neurocytoma	Subependymoma Spinal ependymoma, MYCN-amplified Supratentorial ependymoma, ZFTA or YAP1 fusion-positive

WHO: World Health Organization. IDH-mutant: isocitrate dehydrogenase-mutant. IDH-wt: isocitrate dehydrogenase-wild type. MN1: Meningioma 1. ZFTA: Zinc Finger Translocation Associated. YAP1: Yes-Associated Protein 1.