原始神经外胚叶肿瘤(primitive neuroectodermal tumor,PNET)是神经上皮组织的胚胎性肿瘤,来源于原始神经外胚层细胞,组织学形态分类归属于恶性小圆细胞肿瘤,由幼稚的神经外胚层细胞组成。根据肿瘤发生部位的不同,PNET分为中枢性(cPNET)和外周性(pPNET)两类。由于pPNET和Ewing肉瘤、Askin瘤具有相同的临床表现、形态学特征、免疫组化表型、遗传学特点及临床预后,现已有学者将三者统称为外周性原始神经外胚层肿瘤(pPNETs)[1,2]。 The primitive neuroectodermal tumor (PNET) is an embryonal tumor of neuroepithelial tissue and is derived from primitive neuroectodermal cells. The histopathological classification belongs to malignant small-cell tumor, which is composed of naive neuroectodermal cells . According to different tumor sites, PNET is divided into central (cPNET) and peripheral (pPNET) categories. As pPNET and Ewing’s sarcoma, Askin’s tumor has the same clinical manifestations, morphological features, immunohistochemical phenotype, genetic characteristics and clinical prognosis, there are some scholars have collectively referred to as the three peripheral primitive neuroectodermal tumors (pPNETs) [1,2].