促纤维增生／结节型髓母细胞瘤病理学特点及相关信号通路研究

Analysis of pathological characteristic in desmoplastic/nodular medulloblastoma

目的探讨促纤维增生／结节型髓母细胞瘤（DNMB）的组织病理学特征和瘤细胞分化相关的信号通路。方法采用HE染色、Reticulin染色和免疫组织化学染色等方法，对803例髓母细胞瘤石蜡样本进行分析。结果103例样本（103／803）确诊为DNMB，HE染色显示DNMB存在无网状纤维的结节样苍白岛，并由致密的多形性细胞及网状纤维围绕。所有样本Reticulin染色后，可见结节间存在银染成黑色的网状纤维。免疫组化结果：结节内细胞呈现胞质NSE、Syn阳性表达，胞核Neu-N阳性表达；结节内Ki-67标记指数与结节间相比明显较低；GABl和filaminA抗体染色显示结节间及周围细胞胞质阳性，结节内细胞部分表达；B-catenin抗体染色显示结节内、外细胞胞质阳性，但胞核均为阴性。结论DNMB是髓母细胞瘤中组织学形态较为特殊的亚型，Reticulin染色是重要的诊断方法，该肿瘤细胞分化与SHh信号通路激活存在密切联系。

Objective To analysis clinic pathological characteristic of desmoplastic/nodular medulloblastoma （DNMB）. Methods HE staining, Reticulin staining and immunohistochemisty staining were performed in 803 formalin fixed paraffin embedded tissues of medulloblastomas, to analysis the characteristic of DNMB. Results 103 cases （ 103/803 ） were identified DNMB with typical nodular, reticulin -free zones surrounded by densely intercellular reticulin fiber network. Intranodular cells were positive for NSE, Syn and Neu - N were found in DNMB, and Ki - 67 labeling indices were lower than Internodular regions. Retieulin staining showed positive for reticulin fibers in Internodular regions. Intemodular regions of this DNMB showed strong cytoplasmic staining for GAB1 and filamin A, but negligible reactivity within nodules. Both Intemodular and Intranodular regions showed cytoplasmic staining for[5- catenin. Conclusions DNMB is the distinct subtype of medulloblastoma with characteristic histological appearance, Mechanism of tumorigeness of DNMB is correlates of Sonic Hedgehog pathway.