用透射电子显微镜观察了8例髓母细胞瘤。依其超微结构不同,髓母细胞瘤细胞可分为两种类型:Ⅰ型细胞常聚集成群,核内异染色质较多,呈小块状,异染色质之间散布着疏松的常染色质,核仁清晰可见;Ⅱ型细胞含有均匀分布的常染色质,核仁常不易见到,胞质稀少,部分细胞的胞质中含有直经约20nm的微管。本文还讨论了该瘤的组织起源和超微结构的诊断标准。 Eight cases of medulloblastoma were observed by transmission electron microscopy. According to their ultrastructural differences, medulloblastoma cells can be divided into two types: type I cells often gather in groups, more heterochromatin in the nucleus, were small lumps, scattered between the heterochromatin often loose Chromatin, nucleolus clearly visible; type II cells contain uniform distribution of euchromatin, nucleoli are often not easy to see, sparse cells, some of the cytoplasm contains about 20nm through the microtubules. This article also discusses the diagnosis of tissue origin and ultrastructure of the tumor.