A case of early duodenal cancer observed during follow-up of intraductal papillary mucinous neoplasm

Duodenal cancer is a rare disease that accounts for 0.3％ of all primary gastrointestinal tract cancers. We report the case of an elderly patient diagnosed with and treated for early duodenal cancer detected during follow-up after resection of intraductal papillary mucinous neoplasm (IPMN). An 82-year-old man was diagnosed with IPMN during hospitalization for acute pancreatitis in 2004 and underwent pancreatic resection. In 2008, an elevated lesion measuring 15 mm in size was detected at the anterior wall of the duodenal bulb during gastroscopy. A mucosal lesion was also noted during endoscopic ultrasonography. Histopathological examination of a biopsy specimen identified well-differentiated adenocarcinoma. On the basis of these findings, endoscopic mucosal resection was performed. Although the tumor was resected in two parts, no residual malignancy was noted. Histopathological examination of the resected specimen revealed a 20×18 mm well-differentiated adenocarcinoma, pT1a (m), med, INF-α, ly (-), v (-), pHMx, pVM0. Gastrointestinal endoscopy performed two months after surgery and in 2013 did not show any obvious signs of tumor recurrence. IPMN is sometimes reported to occur in combination with cancers of other organs. However, to our knowledge this is the first case report of early duodenal cancer occurring in a patient with IPMN.