Oncocytic tumor of the pancreas. Report of a case with aspiration cytology.

The fine needle aspiration (FNA) cytologic findings in a case of pancreatic oncocytoma are reported, and the differential diagnoses are discussed. The FNA picture was consistent with an oncocytic, acinar or islet cell neoplasm; electron microscopy was required to make the definitive diagnosis. The partially cystic tumor measured 7 cm and occurred in the head of the pancreas in a 63-year-old man with symptoms related to compression of the common bile duct. The clinical findings in this and a few other known cases indicate that the malignant potential of pancreatic oncocytoma may be low. Thus, it is important to distinguish this type of tumor from the cytologically similar acinar carcinoma of the pancreas, which has a poor prognosis in general.