室管膜瘤是一种罕见的中枢神经系统肿瘤，发生于各个年龄组，是最常见的儿童恶性脑肿瘤之一。直到《WHO脑肿瘤分类第3版》之前，室管膜瘤仅依据组织学特征进行分类，但分子分析的进展使得分子信息首次并入2016年《WHO脑肿瘤分类第4版》的室管膜瘤诊断中。然而，肿瘤级别与生存预后之间的低相关性仍然是一个问题。与其他恶性脑肿瘤不同，室管膜瘤在遗传和表观遗传方面具有特殊的特征，鉴定的点突变很少。甲基化分型被发现能够将室管膜瘤分为不同的亚型，2021年《WHO脑肿瘤分类第5版》采用了基于组织学特征、遗传改变、甲基化模式和解剖位置的新分类。该新分类包括10种诊断实体：1）上颅窝亚室管膜瘤；2）上颅窝室管膜瘤，ZFTA融合阳性；3）上颅窝室管膜瘤，YAP1融合阳性；4）后颅窝亚室管膜瘤；5）后颅窝A类室管膜瘤；6）后颅窝B类室管膜瘤；7）脊髓亚室管膜瘤；8）脊髓室管膜瘤；9）脊髓粘液乳头状室管膜瘤；10）脊髓室管膜瘤，MYCN扩增。先前被接受的“异型室管膜瘤”一词已被取消。与其他中枢神经系统肿瘤一样，基于综合诊断的新分类引入了组织学和分子诊断。本文总结了《WHO脑肿瘤分类第5版》中关于室管膜瘤的分子分类。

Ependymoma is a rare central nervous system tumor that occurs in all age groups and is one of the most common childhood malignant brain tumors. Until the 3rd edition of the WHO Classification of Brain Tumours, ependymoma was classified based solely on histologic findings, but advances in molecular analysis led to the incorporation of molecular information into the diagnosis of ependymoma for the first time in the 2016 WHO Classification, 4th edition. However, the low correlation between tumor grade and survival prognosis remained a problem. Unlike other malignant brain tumors, ependymoma is genetically and epigenetically characterized with few identified point mutations. Methylation profiling was found to classify ependymoma into distinct subgroups, and the 2021 WHO Classification, 5th Edition, adopted new classifications by histologic findings, genetic alterations, methylation patterns, and anatomic location. This new classification includes 10 diagnostic entities: 1)supratentorial subependymoma; 2)supratentorial ependymoma, ZFTA-fusion positive; 3)supratentorial ependymoma, YAP1-fusion positive; 4)posterior fossa subependymoma; 5)posterior fossa group A ependymoma; 6)posterior fossa group B ependymoma; 7)spinal subependymoma; 8)spinal ependymoma; 9)spinal myxopapillary ependymoma; and 10)spinal ependymoma, MYCN-amplified. The previously accepted term "anaplastic ependymoma" was dropped. As with other CNS tumors, a new classification was introduced based on an integrated diagnosis that incorporates histologic and molecular diagnosis. In this article, we summarize the molecular classification of ependymoma in the WHO Classification of Brain Tumours, 5th edition.