What is gastrointestinal mesenchymal tumor? What is the incidence? Who is the most prevalent group? Where does it fit in the family of gastrointestinal tract tumors? What are the development trends? In the past decade or so, a new type of gastrointestinal tumor, gastrointestinal mesenchymal tumor, has gradually entered the public eye and been taken seriously. It has been found that most of the gastrointestinal smooth muscle tumors, smooth muscle sarcomas, nerve sheath tumors and many other tumors diagnosed in the past actually belong to the category of gastrointestinal mesenchymal tumors. Unlike common gastric and intestinal cancers, gastrointestinal mesenchymal tumors do not originate from the mucosal epithelium of the gastrointestinal tract, but from the mucosal muscle layer or intrinsic muscle layer, and are the most common mesenchymal-derived tumors of the gastrointestinal tract, accounting for 1%-2% of all gastrointestinal tumors. Moreover, in terms of pathogenesis, gastrointestinal mesenchymal tumors are also fundamentally different from other GI tract tumors, and most of them have characteristic specific genetic mutations. The disease is more common in middle-aged and elderly people over 50 years of age, and there is little difference in the incidence rate between men and women. Although the incidence of gastrointestinal mesenchymal tumors is not high compared with gastric and intestinal cancers, about 10-20/million people/year, its incidence has shown a trend of increasing year by year in recent years. Epidemiological statistics in East China show that the incidence of gastrointestinal mesenchymal tumors in this region is at a high level worldwide. What are the symptoms of gastrointestinal mesenchymal tumor compared with gastric and intestinal cancers? How destructive is it to the body? Cancer is a malignant tumor that occurs in the epithelium and has the characteristics of infiltrative growth and easy recurrence and metastasis. Gastrointestinal mesenchymal tumors occur in the mesenchymal tissue of the gastrointestinal tract and are less locally invasive than carcinomas and less likely to metastasize through lymph nodes. Previously, GIST was considered to be benign and malignant, but now it is found that even very small GIST may recur or metastasize (the main sites of recurrence or metastasis are liver and peritoneum), so it is now generally considered to be a potentially malignant disease. The risk of recurrence and metastasis of gastrointestinal mesenchymal tumor can be classified into four grades: very low, low, moderate and high, based on indicators such as tumor size, tumor site and cell division activity. Among them, very low and low risk tumors rarely recur or metastasize and can almost be considered benign. However, high-risk gastrointestinal mesenchymal tumors are highly susceptible to recurrence or metastasis after surgery, and before the introduction of the targeted drug Gleevec, the incidence could be as high as 40-90%, with a survival time of only 10-20 months once the metastasis has recurred. The vast majority of recurrences or metastases occur within 2 years of initial resection. What are the treatments for gastrointestinal mesenchymal tumors? What are the results? What is the prognosis? The characteristics, advantages and status of the department in the diagnosis and treatment of gastrointestinal mesenchymal tumors and the development of guidelines are incorporated. Given the heterogeneity of tumors, especially for gastrointestinal mesenchymal tumors, which have completely different regressions after surgical resection with different risks of recurrence and metastasis, individualized treatment plans need to be developed for different patient cases. By reviewing and summarizing the experience of treating nearly 1,000 cases of gastrointestinal mesenchymal tumors over the past decade, the Department of Gastrointestinal Surgery of Renji Hospital of Shanghai Jiao Tong University School of Medicine has established a team specializing in the treatment of gastrointestinal mesenchymal tumors in recent years to make standardized and individualized treatment decisions for all patients admitted with gastrointestinal mesenchymal tumors. Except for some asymptomatic and very small (<50px) tumors, surgical resection is the preferred treatment option for most gastrointestinal mesenchymal tumors. According to the tumor size, location, relationship with adjacent organs and other factors, and taking into account the patient's age and systemic status, the surgical options available for different patients include traditional open surgery, minimally invasive laparoscopic surgery, minimally invasive endoscopic surgery and minimally invasive surgery with endoscopy combined with laparoscopy. The vast majority (>95%) of gastrointestinal mesenchymal tumors can be radically resected through a thorough preoperative evaluation and thorough preoperative preparation. For a subset of patients who are evaluated and judged to be beyond radical resection or too invasive and risky for surgery, tumor shrinkage can be achieved with preoperative treatment with the targeted drug Gleevec, thereby regaining the condition for radical surgery. Patients with gastrointestinal mesenchymal tumors that have developed or have a higher risk (moderate and high risk) of postoperative recurrence and metastasis need to be treated with the targeted drug Gleevec. As a classic representative of targeted oncology drugs, Gleevec has achieved near miraculous efficacy in the treatment of gastrointestinal mesenchymal tumors, with relatively low toxic side effects and effective anti-tumor activity that have benefited tens of thousands of patients with gastrointestinal mesenchymal tumors worldwide. As one of the authorized evaluation sites of the China Charity Federation’s Gastrointestinal Mesenchymal Tumor Patient Assistance Program. How to prevent gastrointestinal mesenchymal tract tumor? When to suspect gastrointestinal mesenchymal tract tumor? Early detection and diagnosis of gastrointestinal mesenchymal tumor is difficult because the site of origin is relatively hidden and the clinical presentation is not specific. Gastrointestinal bleeding is a valuable sign, and all unexplained GI bleeding (such as black stool, vomiting blood, etc.) needs to be examined in a regular hospital as soon as possible to exclude the possibility of GI tumors (including GI mesenchymal tumors and gastric cancer intestinal cancer). Nowadays, we encounter more and more cases of incidental detection of gastric micro mesenchymal tumor (<50px) through physical examination, and the incidence of micro mesenchymal tumor is currently considered to be much higher than expected, and some of them may be stable for life without progression. Therefore, for this group of patients, excessive anxiety is unnecessary and regular follow-up or endoscopic/laparoscopic minimally invasive surgical resection should be performed under the guidance of a specialist physician.