The incidence of gastrinoma is 0.1-15.0 per million, and 0.1% of peptic ulcers and 2-5% of recurrent ulcers are caused by gastrinoma. In China, the incidence of gastrinoma is the third highest among pancreaticoduodenal endocrine tumors, lower than insulinoma and non-functional islet cell tumors. Gastrinoma is a rare disease, and only 78 cases have been reported in the past 40 years since 1965, including 3 cases reported in our hospital (summarized in the Chinese Hospital Digital Library). In 1955, Zollinger and Ellison first reported two cases characterized by persistent ulcers, high gastric acid secretion, and non-B-cell tumors of the pancreas, which were named Zollinger-Ellison Syndrome (ZES). In 1961, Gregory and Tracery extracted the active substance from this tumor and identified it as Gastrin or Gastrin, so they named the tumor as Gastrinoma or Gastrinoma, which is an islet G cell tumor. Clinical symptoms and typing The main clinical manifestations of 78 patients with gastrinoma in China were summarized in order of appearance: upper abdominal discomfort, abdominal pain, gastrointestinal bleeding, vomiting and acid reflux, diarrhea, gastrointestinal perforation, etc. Most patients underwent the first surgery due to upper gastrointestinal bleeding and gastrointestinal perforation, and the most received five surgeries. Most patients underwent the first surgery for upper gastrointestinal bleeding and perforation of the gastrointestinal tract, with a maximum of five surgeries. Those with multiple endocrine neoplasia (MEN-Ⅰ) also have symptoms such as excessive sweating, palpitations, fractures, diplopia, and lactation, and have a clear family history. Gastrinoma is divided into disseminated type and MEN-Ⅰ type, and disseminated type is more common. About 10%-25% of gastrinomas belong to MEN-Ⅰ, which can be combined with lesions of parathyroid gland, pituitary gland, pancreatic islet and adrenal cortex. The tumor growth is relatively slow, the survival time with tumor is long, and the prognosis is good. Diagnosis This disease is rare, and only one to three cases of gastrinoma have been reported in the domestic literature, which is easily ignored by clinicians. The time from the appearance of clinical symptoms to diagnosis in 78 patients reported in China was 2-13 years. The possibility of gastrinoma should be considered clinically in the following points: ① peptic ulcer in adolescents or the elderly with a family history of gastrointestinal secretory disease; ② persistent erosive esophagitis, multiple peptic ulcers, distal duodenal ulcer with diarrhea; ③ endoscopy suggesting thickened gastric and duodenal mucosa; ④ unexplained hyperacidity after gastric and upper abdominal surgery, intestinal fistula and marginal anastomotic ulcer; ⑤ In 1982, the introduction of proton pump inhibitors has changed the typical clinical manifestations of gastrinoma. Therefore, it is necessary to be more alert to the presence of gastrinoma while treating hypergastrinemia. Local diagnosis About 90% of gastrinoma tumors are located in the “gastrinoma triangle”, which is difficult to diagnose because of the non-specific clinical manifestations and the multiple and disseminated nature of gastrinoma. Because of the different benign and malignant tendencies of pancreatic and duodenal gastrinomas, in recent years there has been a lot of emphasis on identifying the site of the tumor, as the treatment varies. Localization of pancreatic gastrinoma Traditional abdominal ultrasonography, CT, MRI and angiography still have a high value in the localization of pancreatic gastrinoma. 1993 prospective comparative study of 32 cases of gastrinoma by the National Institutes of Health showed that the sensitivity of ultrasonography, CT, MRI and angiography were 19%, 28%, 25% and 59%, respectively. However, for the 18 patients with liver metastases, the sensitivity of MRI imaging was 83%, compared with 50% for ultrasound, 56% for CT, and 61% for angiography. The authors concluded that MRI is the imaging test of choice for the evaluation of pancreatic endocrine tumors with liver metastases. In contrast, angiography remains the preferred method for tumor localization in the evaluation of primary pancreatic gastrinoma. In the 1990s, some new methods began to be used for the localization and diagnosis of gastrinoma. Endoscopic ultrasound (EUS): Endoscopic ultrasound can accurately visualize the pancreas and is highly sensitive to small adenocarcinomas, which is an important method for the diagnosis of pancreatic gastrinoma. If endoscopic ultrasound is negative for gastrinoma, pancreatic gastrinoma can be excluded, suggesting small duodenal or extra-pancreatic lesions; ②Somatostatin receptor scintigraphy (SRS): Since gastrointestinal endocrine tumors have high affinity for growth inhibitor receptors, growth inhibitor analogs are labeled with stable indium The growth inhibitory receptor was measured by scintigraphy after binding to growth inhibitory receptor with stable indium-labeled growth inhibitory analogue, octreotide. The detection rate of gastrinoma by SRS was reported to be 100%, and SRS was used clinically in 1989 and has become an important method for the diagnosis of gastrinoma. The principle of SASI is that after the injection of pancreatin, gastrinoma cells will rapidly release a large amount of gastrin. The catheter is inserted selectively into the gastroduodenal artery, superior mesenteric artery and splenic artery. The gastroduodenal artery supplies the head of the pancreas and the upper part of the duodenum; the splenic artery supplies the body and tail of the pancreas; and the superior mesenteric artery supplies the head of the pancreas and the lower part of the duodenum. Another catheter was placed into the right hepatic vein to collect venous blood specimens for the determination of gastrin. The blood was collected from the hepatic vein for gastrin measurement before and 20, 40, 60, 90 and 120 seconds after each injection. The exact location of gastrinoma was determined by the peak of gastrin after selective arterial injection of pancreatin. Imamura reported that gastrinomas were localized in all 12 patients. In 1993, Sugg et al. reported that the proportion of duodenal gastrinomas increased to 77% and the detection rate of all gastrinomas increased to 94% due to the emphasis on duodenal exploration. The detection rate of all gastrinomas increased to 94%. The incidence of duodenal gastrinomas reported in the domestic literature varies widely, which may be related to the awareness of duodenal gastrinomas in the reporting units and the number of cases. The incidence of gastrinoma in the duodenum varies greatly in the domestic literature, which may be related to the awareness of the reporting unit and the number of cases. Some localization methods of pancreatic gastrinoma have some value in the localization of duodenal gastrinoma, but the specificity is not high. Gastroduodenoscopy should be routinely performed in patients with recurrent ulcers or postoperative ulcers, and the third segment of the duodenum should be investigated, and extra care should be taken if duodenal nodules are found, especially when combined with thick and hypertrophic gastric mucosa, multiple erosions, and large amounts of gastric fluid retention, the possibility of gastrinoma should be considered. Jensen recommends that all patients with gastrinoma should be routinely explored through a duodenal incision. The second segment of the duodenum should be incised longitudinally, and the third segment can be explored with a finger or with a duodenoscope, taking care not to miss small lesions. The standard exploratory procedure should also include intraoperative EUS and intraoperative duplex examination of the duodenum, which can clearly localize gastrinomas and have a high positive rate. In conclusion, although there are many methods for preoperative localization and diagnosis, the appropriate method can be selected according to the conditions and equipment. However, whether it is pancreatic gastrinoma or duodenal gastrinoma, careful exploration during surgery can still make up for the lack of preoperative localization. The question of benignity and malignancy of gastrinoma Pathology can confirm the diagnosis of gastrinoma, but there is no reliable basis for determining its benignity and malignancy. Whether gastrinoma is malignant at the beginning or becomes malignant when it is small and grows to 2-3 cm in diameter remains to be investigated. Similar to carcinoid tumors, gastrinomas over 2 cm in diameter are prone to metastases, especially liver metastases. This would explain why primary gastrinomas located in the duodenum are mostly in diameter.