What to do when small lymph nodes are found in the retroperitoneum cannot be generalized, and different treatments should be taken in combination with the specific causes of the lymph nodes. 1. Inflammatory infections: If there is an inflammatory infection in the abdominal cavity, such as pancreatitis, peritonitis, perforation of the posterior wall of the duodenum after the local infection, as well as renal abscess infection, can cause retroperitoneal lymph nodes, for this case can be treated by anti-infective drugs such as macrolides, or direct surgical removal of the infected foci, to be the disappearance of the inflammation, retroperitoneal lymph nodes can slowly subside. 2. Malignant tumors: If the small retroperitoneal lymph nodes are invaded by malignant tumors such as pancreatic malignant tumors and renal malignant tumors, it is necessary to treat the primary disease and clear the lymph nodes and other anti-tumor treatment. It is important to note that small retroperitoneal lymph nodes may be simple lymph nodes, which are only closely observed and do not require special treatment. Therefore, it is necessary to go to the hospital for examination and choose the treatment plan after comprehensive evaluation by the doctor.