Microgastrinomas of the Duodenum

Gastrinomas are now being detected at an earlier stage than was formerly the case. Furthermore, with the ability to control acid secretion, emphasis has been placed on identifying gastrinoma patients who are potentially curable by tumor resection rather than by palliative gastrectomy. Despites estimates suggesting that 20-40% of sporadic gastrinoma patients can be successfully resected for cure, as many as 40% of such patients have occult tumors that elude detection. In an effort to better localize gastrinomas, we have used percutaneous transhepatic venous (THVS) gastrin sampling over the past 10 years. From 1978 to 1988, THVS was used in 46 patients in whom there was no other evidence of metastatic gastrinoma by conventional studies. Gastrinomas were found at operation in all but one patient. The purpose of this report is to emphasize that occult tumors are most often found in the duodenal wall, and frequently they may be no greater than 2 mm in diameter. Five recent cases illustrate that these small tumors or microgastrinomas may be the sole source of hypergastrinemia and can be cured by local excision. These recent cases emphasize that microgastrinomas are not usually palpable through the duodenal wall. They may be detected only after duodenotomy and meticulous evaluation of the mucosa by eversion and direct palpation. Duodenotomy and intraluminal exploration should be considered an essential component of the operation for patients with extrapancreatic gastrinomas.