脑膜瘤是最常见的原发性颅内肿瘤。因此，它们构成了神经病理学实践中诊断标本的主要份额。 2021 年 WHO 中枢神经系统肿瘤分类（“CNS5”）引入了首个针对具有 TERT 启动子致癌变异和 CDKN2A/B 纯合缺失的脑膜瘤的分子分级参数，作为 CNS WHO 3 级标记。在新的分类卷中，不仅要求对新的分类问题进行澄清，而且还要求对脑膜瘤分级中长期存在的问题进行澄清，这些问题超出了世界卫生组织“蓝皮书”的范围。此外，对可能的新分子分级参数的最新研究尚未在 2021 年分类中实施，但构成了令人信服的文献体系。因此，cIMPACT-NOW 指导委员会召集了一个工作组来提供此类澄清并评估可能的新型分子标准的证据。因此，此 cIMPACT-NOW 更新为更标准化的形态学评估和解释提供了指导，最重要的是与脑侵袭有关，确定了建议进行高级分子检测的场景，建议将 CNS WHO 1 级病例指定为 CNS WHO 2 级形态但染色体臂 1p 缺失与 22q 缺失和/或 NF2 致癌变异相结合，并讨论了当前证据尚不足以产生新建议的领域。由牛津大学出版社代表神经肿瘤学会出版2024 年。本作品由 (a) 美国政府雇员撰写，在美国属于公共领域。

Meningiomas are the most frequent primary intracranial tumors. Hence, they constitute a major share of diagnostic specimens in neuropathology practice. The 2021 WHO Classification of Central Nervous System Tumors ("CNS5") has introduced the first molecular grading parameters for meningioma with oncogenic variants in the TERT promoter and homozygous deletion of CDKN2A/B as markers for CNS WHO grade 3. However, after publication of the new classification volume, clarifications were requested, not only on novel but also on long-standing questions in meningioma grading that were beyond the scope of the WHO "blue book". In addition, more recent research into possible new molecular grading parameters could not yet be implemented in the 2021 classification but constitute a compelling body of literature. Hence, the cIMPACT-NOW Steering Committee convened a working group to provide such clarification and assess the evidence of possible novel molecular criteria. As a result, this cIMPACT-NOW update provides guidance for more standardized morphological evaluation and interpretation, most prominently pertaining to brain invasion, identifies scenarios in which advanced molecular testing is recommended, proposes to assign CNS WHO grade 2 for cases with CNS WHO grade 1 morphology but chromosomal arm 1p deletion in combination with 22q deletion and/or NF2 oncogenic variants, and discusses areas in which the current evidence is not yet sufficient to result in new recommendations.Published by Oxford University Press on behalf of the Society for Neuro-Oncology 2024. This work is written by (a) US Government employee(s) and is in the public domain in the US.