A 71-year-old man had been pointed out mild dilation of pancreatic duct at regular health check in 2006. The lesion did not show remarkable change in 2009. However, significant dilation of pancreatic duct was observed, and he developed diabetes mellitus in October 2012. Laboratory data showed elevated serum pancreatic enzymes. Abdominal CT revealed pancreatic lithiasis in the tail. At that time, chronic pancreatitis was anticipated. Abdominal MRI revealed dilatation of the main pancreatic duct and its branches with cystic lesions of the pancreatic head, body, and tail. These results suggested that a cystic lesion of the pancreatic tail grew rapidly and a cystic lesion of the head was malignancy. Total pancreatectomy was performed. The histopathological examination showed IPMC of the pancreatic head and IPMN of the body. There was no neoplastic lesion other than pancreatic lithiasis in the tail. This case report shows that IPMN should be considered as a differential diagnosis when pancreatic lithiasis is observed.
