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

Background: 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. Methods: 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. Results: 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). Conclusion: Significant differences in the clinical and radiographic features exist among CNS5 glioma subtypes, informing potential diagnosis, management and prognosis at initial presentation.