Different sizes of pancreatic cystic adenoma have different clinical manifestations and different treatment methods as follows: 1. Plasmacytic cystic adenoma of the pancreas: surgery is not advocated for less than six centimeters, and surgery is recommended for more than six centimeters, but it is not very urgent and can be followed up. 2. Mucinous cystic adenoma of the pancreas: surgery is recommended for more than four centimeters in clinical opinion, and close follow-up for less than four centimeters. 3. During follow-up, plasmacytic cystic adenoma or mucinous cystic adenoma, if the tumor has recently increased rapidly, showing obvious clinical symptoms, or even biliary or pancreatic compression symptoms, causing clinical manifestations of pancreatitis, it is recommended to do surgery. In pancreatic cystadenoma, because it is a benign tumor, the scope of surgery is not large and is determined by the size and location of the tumor.