（IPMN (intraductal papillary mucinous neoplasms of the pancreas) was first described in the literature in the early 1980s as a pancreatic neoplasm characterized by a large amount of mucus floating in the Vater’s abdomen under endoscopy. The term IPMN was finally recognized and accepted by the World Health Organization in 1996. IPMN of the pancreas is characterized by varying degrees of cystic dilatation of the pancreatic ducts, which can occur anywhere in the ductal system, more commonly in the head and leptomen than in the tail of the pancreas. The main pancreatic duct lesion is the main pancreatic duct, and some patients show invasion of the branch pancreatic ducts, which are usually found in the pancreatic ducts of the leptomen, constituting a branching manifestation, and in a few patients, both the main pancreatic duct and the branch pancreatic ducts are invaded, which is a mixed type. IPMN of main pancreatic duct and branch pancreatic duct origin can have different tumor biology and prognosis, most of the branch pancreatic duct type IPMN are benign lesions, while the other two types are more often malignant, and up to 60% of patients with main pancreatic duct type IPMN are malignant. Epidemiology: The incidence of pancreatic IPMN is low, and foreign literature reports that it accounts for about 2% to 7% of all pancreatic tumors. It is more common in elderly patients with an average age of 60-70 years old, with slightly more males than females (male:female = 1. 33:1). Etiology: The molecular biological mechanism of IPMN is still unclear, but it has been shown that K-ras gene mutation is very close to it. Pathology: Histopathologically, IPMN is divided into four categories: (1) intraductal papillary mucinous adenoma of the pancreas; (2) junctional intraductal papillary mucinous adenoma of the pancreas; (3) intraductal papillary mucinous adenocarcinoma in situ of the pancreas; (4) intraductal papillary mucinous adenocarcinoma of the pancreas. The first three categories are considered as non-invasive damage without metastatic behavior. In addition, IPMNs are classified into main duct type, branch duct type and mixed type according to the ductal site of tumor development. Clinical manifestations: The most common symptoms include abdominal pain, weight loss, jaundice and steatorrhea. Some patients are asymptomatic and are detected on physical examination with CT or MRI. Ultrasound can detect dilated pancreatic ducts or cystic lesions, but it is difficult to distinguish mucin-like material from pancreatic parenchyma. The characteristic features of IPMN in CT or MRCP are partial or extensive dilatation of the pancreatic ductal system. IPMN retains the morphology of an intraductal or intracapsular papillary tumor even when it infiltrates the pancreatic stroma and forms a solid tumor, which is the main point of differentiating IPMN from pancreatic ductal carcinoma in CT. MRCP can more accurately show the cystic dilatation of the branched pancreatic ducts and the intracapsular septa and cystic nodules, and is more effective than ERCP in estimating the size and extent of the tumor. The earliest case report of IPMN is about its features under ERCP: including the enlarged papilla of Vater’s jugular with enlarged opening and mucin secretion under duodenoscopy; after pancreatic ductography, total pancreatic duct tumor can be seen as total pancreatic duct dilatation with filling defect due to mucin or tumor; branch pancreatic duct tumor can be seen as branch pancreatic duct cystic dilatation with or without filling defect, which can be accompanied by total pancreatic duct dilatation. ERCP can also perform pancreatic fluid tumor markers, cytological examination and tumor biopsy. Treatment and prognosis: A few scholars believe that benign IPMN can be followed up and observed, but the majority of scholars believe that once the disease is diagnosed, radical surgical resection should be actively performed. Because IPMN has a certain tendency to become malignant and the surgical resection rate of IPMN is high and the results are good. The recommended surgical procedures include pancreatic head and duodenectomy, caudal pancreatic resection, total pancreatectomy, etc. The prognosis of IPMN is good. Foreign scholars reported that the 5-year survival rate and 10-year survival rate of surgically treated IPMN are 75% and 60%, respectively.