Intraductal papillary mucinous neoplasm (IPMN) is a rare pancreatic cystic tumor originating from the pancreatic ductal epithelium that grows in a papillary pattern and secretes excessive mucus, causing progressive dilatation or cystic changes of the main pancreatic duct and/or branch pancreatic ducts. IPMN occurs in the elderly, most often in the age of 60-70 years, the ratio of men to women is about 2:1. Clinical symptoms and signs depend on the degree of ductal dilatation and the amount of mucus produced. It may present with epigastric pain and malaise, or it may produce the clinical manifestations of chronic pancreatitis or even an acute attack due to obstruction of pancreatic fluid outflow. The tumor may grow in a restricted manner or spread along the main or branch pancreatic ducts, resulting in progressive dilatation of the adjacent main or branch pancreatic ducts. The dilated ducts secrete large amounts of mucus, and tumors located in the pancreatic head and leptomeningeal region may protrude into the duodenum, causing mucus to flow into the intestinal lumen from the enlarged duodenal papilla. Microscopically, the tumor is seen to be lined with numerous small papillae and covered with columnar epithelium. The degree of epithelial differentiation varies widely, ranging from atypical hyperplasia to papillary adenomas or adenocarcinomas, or a mixture of these. For branching type ipmn that is solitary in the pancreatic leptomeninges and the tumor diameter is <2.5 cm, it can be closely observed clinically, while for other types of IPMN, it should be aggressively surgically resected because of its potentially malignant features.