目的 :观察外周型原始神经外胚层瘤 (pPNET)的临床病理及免疫组化特征。 方法 :对 10例 pPNET进行组织形态学观察及免疫组织化学和组织化学染色。结果 :形态学上表现为小圆细胞性呈大片状排列 ,其间可见纤维结缔组织间隔 ,瘤细胞呈非典型性菊形团样结构 ;免疫组化显示NSE呈 10 0 %表达 ,Syn、S 10 0蛋白和Vim分别为 80 % (8/ 10 )、6 0 % (6 / 10 )和6 6 7% (6 / 9)。结论 :根据临床表现、组织形态学特征及其免疫组化表型有助于 pPNET的诊断。 Objective: To observe the clinicopathological and immunohistochemical features of peripheral primitive primitive neuroectodermal tumors (pPNET). Methods: Morphological observation, immunohistochemistry and histochemical staining were performed on 10 cases of pPNET. RESULTS: Morphologically, small round cells were arranged in large sheets. The fibrous connective tissue septum was seen between them. The tumor cells showed a non-typical chrysanthemum-like structure. Immunohistochemistry showed NSE expression was 10%, Syn, S Protein 10 and Vim were 80% (8/10), 60% (6/10), and 66.7% (6/9), respectively. Conclusion : According to the clinical manifestations, histomorphological features and immunohistochemical phenotype, it is helpful for the diagnosis of pPNET.