Presenting clinical and radiographic features of diffuse glioma molecular subtypes in accordance with the 2021 CNS5...

The incorporation of molecular parameters into WHO CNS5 has led to reclassification of gliomas. We describe presenting clinical and radiographic features of diffuse adult gliomas according to CNS5 category.

We reviewed pathology reports, clinical and MRI data at presentation of 972 adult patients with glioma between January 2010 and February 2022. Continuous variables were presented as median; categorical variables as numbers and percentages. Comparison was performed using Fisher's exact test.

Seven hundred and thirty-six patients had sufficient data for CNS5 reclassification: Grade 2 IDH mutant (IDHmut) astrocytoma (A2) n = 69, grade 3 IDHmut astrocytoma (A3) n = 37, grade 4 IDHmut astrocytoma (A4), n = 32, grade 2 oligodendroglioma (O2) n = 60, grade 3 oligodendroglioma (O3) n = 23, and IDH-wildtype glioblastoma (GBM) n = 515. Age at presentation differed between grades 2 and 3 gliomas and grade 4 (mean age: 39 vs 61.7; P < .001); A4 were younger than GBM (39.8 vs 63.1). Seizure was more common in IDHmut gliomas than GBM (58.4% vs 31.8%; P < .001); cognitive impairment was more common in GBM than in IDHmut gliomas (64.4% vs 34.4%; P < .001) and A4 (64% vs 40.6%; P = 0.013). Focal deficits were more frequent in GBM than IDHmut gliomas (74.2% vs 30.5%; P < .001). Contrast enhancement was more frequent in GBM than IDHmut gliomas (93% vs 48%; P < .001), similar with A4 (93% vs 96%; P = 1.00). Minimum apparent diffusion coefficient was higher in IDHmut glioma than GBM (P < .001). Calcification was more common in oligodendroglioma than astrocytoma and GBM (P < .001).

Significant differences in the clinical and radiographic features exist among CNS5 glioma subtypes, informing potential diagnosis, management and prognosis at initial presentation.