Pancreatoblastoma in an adult.

A 37-year-old man with a history of abdominal pain, diarrhea, and weight loss was found to have an 8-cm-diameter tumor in the head of the pancreas, a biopsy specimen of which revealed histologically and ultrastructurally typical pancreatoblastoma. The tumor was unresectable and demonstrated no response to chemotherapy; however, substantial tumor shrinkage resulted from intraoperative and external beam radiation therapy. This rare tumor, to our knowledge not previously reported in an adult, should be considered in the differential diagnosis of adults as well as children with pancreatic epithelial tumors.