The severity of duodenal mesenchymal tumor is as follows: 1. If the tumor is small in size, it is generally harmless; if the tumor is large in size, patients need to undergo surgery, which can cause certain risks due to the high degree of delicacy in the duodenal region, and therefore the surgery is more demanding; 2. Patients whose lesions are located at the junction of biliopancreatic and duodenal cannot undergo local resection, and need to undergo a larger scale pancreaticoduodenectomy, which causes greater trauma and risk; 3. Patients whose lesions are located in the area of the horizontal segment of duodenum, including the upper jejunum, are more common, and generally have late detection and larger tumors, which make surgical treatment relatively difficult.