A giant intraductal papillary mucinous neoplasm of the pancreas which was resectable by cystectomy

The patient was an 85-year-old woman with poor appetite and fatigue. She was referred to us after a giant cystic tumor was observed on abdominal US. CT revealed a 15-cm cystic lesion that extended to the pelvis and scattered nodular lesions with contrast enhancement, which suggested a malignant tumor. ERCP showed communication with the pancreatic duct at the pancreatic head, indicating an intraductal papillary mucinous neoplasm (IPMN). The cyst protruding outside the pancreas was resected, and the surgery was finished after no tumor progression into the pancreatic duct stump was observed. Histopathological examination indicated an IPMN with low-to-intermediategrade dysplasia. Genetic analysis of a nodular lesion showed a GNAS mutation, confirming the diagnosis of IPMN. The rarity of the morphology in this case provides many suggestions for preoperative and postoperative diagnoses, selecting operative procedures, and other related matters.