[A Case of Intraductal Papillary Mucinous Carcinoma with Difficult Preoperative Diagnosis].

Intraductal papillary mucinous neoplasms(IPMN)are common type of pancreatic cystic tumor, and because of their malignant potential, regular imaging follow-up is necessary. In this report, we described a surgically treated case of IPMN in which a malignant tumor could not be ruled out by preoperative diagnosis. The patient was a 75-year-old woman. An enhanced abdominal CT performed during the follow-up after surgery for uterine cancer revealed a cystic lesion with calcification in the tail of the pancreas. Maximum diameter of the cystic lesion was approximately 26 mm. Magnetic resonance cholangiopancreatography(MRCP)showed a cystic lesion in the tail of the pancreas connected to the main pancreatic duct, and the main pancreatic duct was dilated. We followed up the images, assuming it was IPMN, but the tumor size increased over time and the diameter of the main pancreatic duct was dilated. Therefore, malignant diseases could not be ruled out, then laparoscopic distal pancreatectomy and splenectomy were performed. The pathological findings showed a diagnosis of intraductal papillary mucinous carcinoma(IPMC).