Primitive neuroectodermal tumor of the pancreas.

Primitive neuroectodermal tumors (PNETs) are rare small round cell malignancies closely related to Ewing's sarcoma. Involvement of the abdominal cavity, specifically the pancreas, is extremely rare. PNETs affect predominantly children and young adults. The clinical presentation is mostly vague, with a short history of symptoms even in metastatic disease. Findings on imaging studies are nonspecific. The diagnosis can be suggested by the microscopic appearance of the tumor cells, but should be confirmed by histology, immunohistochemistry, fluorescence in situ hybridization, immunoreactivity evaluation of MIC2-protein (CD99) expression, and when possible testing for the chromosome translocation t(11;22) (q24,q12). In adults, the prognosis is poor with no standard treatment. Here, we present a case of pancreatic PNET in a 61-year-old man who presented with persistent abdominal pain and weight loss.