Primitive neuroectodermal tumors(PNETs) are composed of undifferentiated cells resembling germinal matrix cells of the embryonic neural tube. The concept of the primitive neuroectodermal tumors is controversial due to indistinct clinicopathologic enti...
Primitive neuroectodermal tumors(PNETs) are composed of undifferentiated cells resembling germinal matrix cells of the embryonic neural tube. The concept of the primitive neuroectodermal tumors is controversial due to indistinct clinicopathologic entities. While some neuropathologists believe that the PNET concept should be applied to all these tumors with the addition of qualifying terms, the opponents of this approach believe this concept to be too simplistic and that well-established diagnostic entities should not be grouped together as a single entity. Four patients with PNET were reviewed. Although the PNETs bear some differences to posterior fossa medulloblastomas, we should be grouped together as a single pathologic entity because of their primitive nature. The purpose of this study is to review the similarities and differences between two tumors from their histologic and embryologic features.