. 2024 Nov 6;10(6):e70009. doi: 10.1002/2056-4538.70009

Table 1.

Diagnostic criteria

	Essential criteria	Additional information
Astrocytoma, IDH‐mutant	Diffusely infiltrating glioma AND IDH‐mutation AND ATRX mutation OR exclusion of whole arm deletions of 1p and 19q	ATRX mutation can be demonstrated as loss of nuclear ATRX expression on immunohistochemistry or ATRX mutation on molecular testing.
Oligodendroglioma, IDH‐mutant 1p/19q‐codeleted	Diffusely infiltrating glioma AND IDH‐mutation AND Whole arm deletions of 1p and 19q	Recommended that 1p/19q assays be able to detect whole‐arm chromosomal losses, such as FISH or molecular genetic testing.
Glioblastoma, IDH‐wildtype	Diffuse astrocytic glioma AND IDH‐wildtype AND H3‐wildtype	Must additionally demonstrate one or more of: microvascular proliferation, necrosis, TERT promoter mutation, EGFR gene amplification, chromosome +7/−10 copy number alterations.

Essential criteria

Additional information

Astrocytoma,

IDH‐mutant

Diffusely infiltrating glioma AND

IDH‐mutation AND

ATRX mutation OR

exclusion of whole arm deletions of 1p and 19q

ATRX mutation can be demonstrated as loss of nuclear ATRX expression on immunohistochemistry or ATRX mutation on molecular testing.

Oligodendroglioma,

IDH‐mutant 1p/19q‐codeleted

Diffusely infiltrating glioma AND

IDH‐mutation AND

Whole arm deletions of 1p and 19q

Recommended that 1p/19q assays be able to detect whole‐arm chromosomal losses, such as FISH or molecular genetic testing.

Glioblastoma,

IDH‐wildtype

Diffuse astrocytic glioma AND

IDH‐wildtype AND

H3‐wildtype

Must additionally demonstrate one or more of: microvascular proliferation, necrosis, TERT promoter mutation, EGFR gene amplification, chromosome +7/−10 copy number alterations.

This table summarises the diagnostic criteria for the neuropathological diagnosis of adult‐type diffuse gliomas according to WHO CNS fifth edition [9]. Once a diffusely infiltrating glioma has been identified on histopathology, these criteria must be demonstrated either by immunohistochemistry or DNA sequencing. Alternatively, DNA methylation profiling can also be used. WHO CNS5 also recommends that grade is designated in Arabic numerals, rather than Roman numerals, as in previous editions.