中枢性原始神经外胚层肿瘤的临床病理分析

A clinicopathological analysis of primitive neuroectodermal tumors of the CNS

目的探讨小脑髓母细胞瘤（ＭＢ）和大脑原发性小细胞肿瘤的组织起源，形态特征及生物学行为的异同。方法采用组织病理学和免疫组织化学方法对２１０例ＭＢ和９例大脑原发性小细胞肿瘤的组织形态特征和标志物表达进行比较研究。结果组织形态学观察显示两者均可向神经元和神经胶质分化。免疫组化标记显示６３２％（６７／１０６例）的ＭＢ和５／８例的大脑原发性小细胞肿瘤可同时表达神经元标志物———突触素（Ｓｙｎ）和神经胶质标志物———胶质纤维酸性蛋白（ＧＦＡＰ）。随访结果显示两者均为高度恶性肿瘤，１年生存率分别为３４６３％和２５６５％，统计分析表明肿瘤有灶状坏死、增殖细胞核抗原标记指数高及术后未进行放疗者预后差（Ｐ＜０００１，Ｐ＜００５，Ｐ＝０．０００１）。结论小脑ＭＢ和大脑原发性小细胞肿瘤的形态特征、标志物表达及生物学行为相同。

Objective To investigate the difference between cerebellar medulloblastoma (MB) and primary cerebral small cell tumor in histogenesis, morphologic features and biological behavior. Methods 210 cases of MB and 9 cases of small cell tumor of cerebrum were observed with histologic and immunohistochemical techniques. Results Both tumors were composed of primitive cells with focal evidence of glial and/or neuronal differentiation. In 63.2% of MB and fiveeighths of small cell tumor of cerebrum coexpressed GFAP and Syn. Both types of tumors were highly malignant. The overall 1 year survival rates were 34.63% and 25.65% respectively. The survival rate was lower for patients with high proliferative index, with necrosis or without receiving radiation therapy. Conclusion MB is similar to other small cell tumors of CNS in morphological features, specific marker expression and biological behavior. These tumors can be classified as primitive neuroectodermal tumors (PNET).