Gastrointestinal cancer is a malignant tumor originating from the mucosal epithelium of the digestive tract, which usually has symptoms such as bleeding and obstruction, and to a certain extent, metastasis or compression of adjacent organs. Many people are not aware of the fact that tumors can easily appear outside the mucosa of the digestive tract. The wall of the digestive tract is a multi-layered structure, and tumors can occur in the layers outside the mucosa, such as gastrointestinal mesenchymal tumors, smooth muscle tumors, lipomas, etc. The malignant ones are usually called sarcomas. Treatment options for these diseases rely mainly on surgical resection. In hospitals with sufficient experience, most cases can be accomplished by laparoscopic surgery, which greatly reduces the trauma associated with the surgery itself without reducing the surgical outcome or increasing the risk of surgery. So, does every case of extramucosal gastrointestinal tumor require surgical treatment? Of course not, extramucosal can also be divided into several layers. For tumors in the submucosal layer, they can often be removed directly through gastroscopy or enteroscopy without incision and without the involvement of laparoscopic surgery, as in the case of gastrointestinal polyps. Even some small tumors in the muscular layer can be implemented for complete treatment by the current advanced ESD technique. Endoscopic resection is one of the least invasive methods. For gastric and colonic sites, perforation and bleeding that cannot be safely disposed of endoscopically may occur in a few cases and require the application of laparoscopic surgery to deal with the problem. Therefore, for cases of submucosal tumors of the stomach and colon, it is most reasonable to choose endoscopic treatment. The treatment of submucosal tumors of duodenum is relatively special. On the one hand, the technical requirements for endoscopic treatment here are higher, and on the other hand, the endoscopic surgery here is larger. However, the risk and degree of trauma of open surgery here are also much greater than those in the stomach and colon. Therefore, endoscopic management of mucosal or extra-mucosal tumors of the duodenum is of greater significance. Having said that, we should know that a proper preoperative evaluation is very, very important for submucosal tumors of the duodenum. A surgeon who can perform both endoscopic surgery and laparoscopic or surgical procedures can perform a field examination of a particular case to get a most pertinent assessment. Why operate when you can do endoscopic surgery. The following is a case that has decided to come in for open surgery. We did another duodenoscopy to evaluate the submucosal tumor in this case and found that the wide base of this submucosal tumor could be snared with a trap, so endoscopic surgery was decisively recommended.