[Pathological Diagnosis and Genetic Alterations of Meningioma].

Meningiomas, renowned for their histological diversity, are one of the most prevalent brain tumors. Some meningiomas show unusual histomorphology, especially in intraoperative rapid diagnosis. Therefore, clinical and radiological information is crucial for pathological diagnosis. Before the 2021 World Health Organization Classification of Tumors of the Central Nervous System(5th edition), pathological diagnosis relied solely on histopathological features. However, this classification introduced new diagnostic criteria for anaplastic meningiomas, which now include promoter mutations and the homozygous deletion of , indicating the necessity of genetic analysis. Some rhabdoid and papillary meningiomas have alterations, which tend to demonstrate an aggressive clinical course and may represent a phenotype of -related tumor predisposition syndrome. Heterozygous deletion of and loss of H3 p.K28me3(K27me3)are also associated with poor prognosis. Although some immunohistochemical markers like MTAP may serve as surrogates for the homozygous deletion of , genetic analysis is required to confirm promoter mutations. Therefore, in routine clinical practice, neurosurgeons and pathologists prioritize appropriate formalin fixation to facilitate genetic analysis using pathological specimens.