Gastrointestinal tumor is the channel of food digestion and absorption, but with the accelerated pace of life, the incidence of gastrointestinal tumor is increasing, but most people are still unfamiliar with gastrointestinal mesenchymal tumor. Gastrointestinal mesenchymal tumor accounts for 1-5% of digestive tract tumors, and it is often difficult to be detected early and easily misdiagnosed. If you have long-term stomach discomfort or unexplained stomach pain, you should be alert to whether you are suffering from gastrointestinal mesenchymal tumor. The youngest malignant tumor Gastrointestinal mesenchymal tumor (GIST) is arguably the youngest malignant tumor, and it was only named in 1998 by a Japanese scholar who discovered its driver gene. Our digestive tract has four layers: mucosa, submucosa, muscular layer and plasma membrane. Despite its name, GIST is actually a malignant tumor that destroys the normal tissue structure and carries the risk of metastasis. As a tumor of mesenchymal origin in the gastrointestinal tract, it has long been mistaken for a smooth muscle-derived tumor that can occur anywhere in the GI tract, with the stomach being the most common. It is also different from “gastric cancer” or “intestinal cancer” of epithelial origin, and the treatment pattern is also very different. The reason why gastrointestinal mesenchymal tumors are easily misdiagnosed is that not only are the symptoms of gastrointestinal mesenchymal tumors hidden early in the course of the disease, but also the clinical symptoms are not specific. If the lesion is in the stomach, it may manifest as indigestion, stomach pain, and epigastric discomfort; if the lesion is in the small intestine, it may manifest as abdominal pain and indigestion; if the lesion is in the rectum, it may cause difficulty in stool, foreign body sensation, and urgency and heaviness. Unlike other GI tumors, it is difficult to detect gastrointestinal mesenchymal tumors with gastroscopy because they tend to develop “inward”, i.e., toward the plasma membrane. In clinical practice, they often find that some patients have metastatic lesions, but the mucosa is still intact and undamaged during gastrointestinal examination. Although it is difficult to “detect” gastrointestinal mesenchymal tumors by gastroscopy, they are still difficult to escape the “eye” of CT. Therefore, it is recommended that if you have long-term stomach discomfort, or unexplained stomach pain, or a feeling of foreign body in the bowel, and the colonoscopy is normal, you may want to have a CT examination. Don’t give up lightly However, fortunately, although gastrointestinal mesenchymal tumor is difficult to find, the treatment effect is still good, and patients diagnosed with gastrointestinal mesenchymal tumor don’t give up lightly. Associate Professor Deng Yanhong said that for gastrointestinal mesenchymal tumors without metastasis, surgery is the preferred treatment with a 5-year survival rate of 90 percent after surgery, and doctors decide whether follow-up medication is needed after surgery based on the risk of metastasis of tumor cells. For gastrointestinal mesenchymal tumors that have metastasized, the 5-year survival rate after treatment is still 50% because the driver gene, c-kit, has been identified and targeted drugs are available for this driver gene. Due to the good treatment effect of this disease, it is important to pay attention to the identification and exclusion of this disease when metastatic tumors in the abdominal cavity are found to avoid misdiagnosis and missed treatment opportunities.