中枢神经系统原始神经外胚层肿瘤(Primitive Neuroectodermal tumor of Central Nervous system)指发生于颅内、视网膜、筛板,起源于原始的神经上皮、形态学上及生物学行为类似的一大类肿瘤的统称。由于与胚胎发生有一定的关系,也有的称为胚胎性神经上皮肿瘤。这类肿瘤多发生于儿童。组织学上由原始神经上皮细胞构成,常表现出一定的分化方向。临床过程发展快,预后较差。如果是颅内的原始神经外胚 Central nervous system primitive neuroectodermal tumor (Primitive Neuroectodermal tumor of Central Nervous system) refers to occur in the brain, the retina, the sieve plate, originated in the original neuroepithelial, morphological and biological behavior similar to a general category of tumor . Due to the embryo has a certain relationship, also known as embryonic neuroepithelial tumors. These tumors occur in children. Histologically composed of primitive neuroepithelial cells, often showing a certain direction of differentiation. Rapid clinical development, the prognosis is poor. If it is intracranial primitive neuroectoderm