Analysis of the WHO Classification of Tumors of the Central Nervous System (fifth edition) in glioma: 60 cases report

Abstract

Objective Histological morphology, immunophenotype and molecular diagnosis of gliomas were reported and classified according to fifth edition of the 2021 World Health Organization (WHO) Classification of Tumors of the Central Nervous System (WHO CNS5). Methods Total 60 glioma patients with a clear diagnosis through genetic testing were collected in General Hospital of Southern Theatre Command of Chinese PLA from July 2019 to July 2021. All of them were diagnosed based on histopathology and molecular alterations by HE staining, immunohistochemical staining, and genetic screening and were classified according to the WHO CNS5. Results A total of 60 gliomas, according to WHO CNS5, were classified into one with pilocytic astrocytoma (1.67%), one with ganglioglioma (1.67%), 15 with astrocytomas, IDH⁃mutant (25%), 11 with oligodendrogliomas, IDH⁃mutant and 1p/19q co⁃deleted (18.33%), one with pleomorphic xanthoastrocytoma (1.67%), 21 with glioblastomas, IDH⁃wildtype (35%), 3 with diffuse midline glioma, H3 K27⁃altered (5%) and 7 with glioma, NEC (11.67%). The 7 patients with glioma, NEC were respectively diagnosed based on histopathology as anaplastic astrocytoma in one case, oligodendrogliomas in 2 cases, diffuse astrocytomas in 2 cases, ganglioglioma in one case, and anaplastic oligodendroglioma in one case, with only one case with methylguanine⁃DNA methyltransferase (MGMT) promoter methylation and one case with BRAF V600E mutation by genetic screening. The 21 patients with glioblastoma, IDH⁃wildtype were respectively diagnosed based on histopathology as glioblastoma in 15 cases, oligodendroglioma in one case, anaplastic oligodendroglioma in 2 cases, diffuse astrocytoma in 2 cases and anaplastic astrocytoma in one case, while TERT promoter mutation in 15 cases (71.43%), EGFR amplification in 7 cases (33.33%), MGMT promoter methylation in 5 patients (23.81%) and amplification of chromosome 7 in one case (4.76%). The 15 patients with astrocytoma, IDH⁃mutant, CNS WHO grade 2-4 were diagnosed based on histopathology as glioblastoma in 3 cases, oligodendroglioma in 2 cases, anaplastic oligodendroglioma in one case, diffuse astrocytoma in 8 cases and anaplastic astrocytoma in one case, with MGMT promoter methylation in 11 cases, homozygous deletion of cyclin⁃dependent kinase inhibitor 2A/B (CDKN2A/B) in 2 cases. Conclusions This article is the first pathological diagnosis report of single⁃center glioma since the publication of WHO CNS5, suggesting the WHO CNS5 could more accurately classify gliomas. However, the proportion of glioma, NEC diagnosed is still relatively high. Even well⁃classified gliomas have many differences in genetic signature. The molecular features of gliomas still require further deeply exploration.

doi：10.3969/j.issn.1672⁃6731.2022.12.014