Recurrent intraductal papillary mucinous neoplasms of the pancreas mimicking ampullary cancer

Although several studies have reported that some patients developed metachronous/recurrent intraductal papillary mucinous neoplasms (IPMNs) after partial pancreatectomy, recurrence of IPMN mimicking ampullary cancer is extremely rare. We report the case of a 62-year-old man who developed recurrent IPMN mimicking ampullary cancer. Every 3-6 months, the patient had received surveillance with computed tomography after distal pancreatectomy for IPMN, high-grade, pancreatobiliary type. However, a villous tumor at the major duodenal papilla was found incidentally by upper gastrointestinal endoscopy 2 years and 3 months after initial surgery, and the biopsy result was adenocarcinoma. Endoscopic ultrasonography showed a tumor at the periampullary lesion; however, the origin of the tumor could not be determined definitively. Remnant total pancreatectomy was performed, and the histological diagnosis revealed IPMN, high-grade, pancreatobiliary type. Some patients develop recurrent IPMN mimicking ampullary cancer; thus, careful surveillance for periampullary lesions as well as remnant pancreas should be performed.