Radiologic findings of peripheral primitive neuroectodermal tumor arising in the retroperitoneum.

OBJECTIVE: The purpose of this article is to present the radiological findings of peripheral primitive neuroectodermal tumors that arise in the retroperitoneum. CONCLUSION: Peripheral primitive neuroectodermal tumors (PNETs) arising in the retroperitoneum tend to be large and aggressive. Although the imaging appearance of peripheral PNETs is nonspecific, these tumors should be considered in the differential diagnosis when one encounters a large retroperitoneal mass with aggressive features.