Primitive neuroectodermal tumor of the pancreas. An extremely rare tumor. Case report and review of the literature.

Peripheral primitive neuroectodermal tumor (PPNET) is a malignant neoplasm of the peripheral nervous system and soft tissues. Representing the fourth case published we herein report a PPNET arising in the pancreas of a six year old girl. She presented with severe anemia due to ulcerative tumor growth and hemorrhage into the duodenum. From the first biopsy pancreatoblastoma was considered as histological diagnosis. Therefore pancreato-duodenectomy was successfully performed. Immunohistochemically, the tumor cells were positive for cytokeratines and several neuronal markers. Due to focal membranous staining for MIC-2 gene product and rosettes in one lymph node metastasis the diagnosis had to be altered into PPNET. This was confirmed by cytogenetic analysis. We conclude that the interpretation of histologic sample excisions from pediatric pancreatic neoplasms may be difficult and that PPNET should be included in the differential diagnosis.