Pancreatic intraductal papillary mucinous neoplasm with anomaly of the portal venous system: Absence of superior mesenteric vein

Abstract

An intraductal papillary mucinous neoplasm (IPMN) was detected in a 74-year-old woman and observed by a primary physician. The size of the cyst and nodule had increased by the time of follow-up by endoscopic ultrasound. A preoperative abdominal CT showed a 20-mm segmented solid tumor inside of a 35-mm cystic mass in the pancreatic head and some 20-mm cysts in the pancreatic body. While it was difficult to identify the superior mesenteric vein (SMV) by CT, MRI showed multilocular cyst crossing to the main pancreatic duct. With diagnosed branched-type IPMN, and pancreatoduodenectomy was performed. There were many collateral veins at the pancreatic head and hepato-duodenal ligament. We searched for SMV thoroughly from the splenic vein to the inferior mesenteric vein, but it was not detected. Therefore, this case was diagnosed as IPMN accompanying SMV absence.