A six-centimeter mass in the tail of the pancreas without pancreatic duct dilatation may be caused by pancreatic pseudocyst, pancreatic cystic tumor or pancreatic cancer, which can be followed up and observed or treated by surgery. 1. Pancreatic pseudocyst: six-centimeter pancreatic cysts without symptoms do not need treatment and can be observed dynamically, and the cysts may be self-absorbed. If abdominal pain, bleeding and other complications occur, surgical treatment can be performed. Surgical methods include internal drainage, external drainage and pancreatic pseudocyst excision. 2. Pancreatic cystic tumor: the treatment of six-centimeter pancreatic cystic tumor should be decided according to the histological category of the tumor. For example, plasma cystadenoma has a low chance of malignant transformation, no symptoms can be observed and followed up, and surgical resection will be performed only when there are symptoms; while mucinous cystadenoma has a tendency of malignant transformation, and should be actively operated upon discovery in general. 3. Pancreatic cancer: six centimeters of pancreatic cancer is often treated by surgery, and the surgical plan is usually pancreatic body tail resection, and patients who cannot be resected by surgery can be treated with radiotherapy, chemotherapy (e.g. Gemcitabine, Albumin Paclitaxel, etc.) and other comprehensive treatment measures, and at the same time, supportive treatments such as nutritional support and pain relief can be taken. The tail of the pancreas has a six-centimeter mass, the pancreatic duct is not dilated should be timely to go to the hospital, improve the examination, clear the cause of the disease to give targeted treatment.