Localization of gastrinomas by endoscopic ultrasonography in patients with Zollinger-Ellison syndrome.

BACKGROUND: Preoperative localization of gastrinomas by current imaging techniques such as computed tomography (CT) scan and angiography is still difficult because of the small size of tumor(s) in most patients undergoing operation. This study evaluated the diagnostic value of endoscopic ultrasonography.

METHODS: Twenty-two patients presenting with Zollinger-Ellison syndrome underwent exploratory laparotomy after preoperative attempts to identify the gastrinoma(s) by CT scan, upper gastrointestinal endoscopy, and endoscopic ultrasonography. Surgery included intraoperative ultrasonography and duodenal transillumination in all cases. The sensitivity and specificity of imaging techniques were then evaluated.

RESULTS: At least one tumor was found in 19 patients (four had two tumors and one had multiple tumors). Duodenal, lymph node, and pancreatic gastrinomas were found in 42%, 38%, and 17% of the patients, respectively. Sensitivity of endoscopic ultrasonography was 50% for duodenal wall tumors (conventional endoscopy, 40%), 75% for pancreatic tumors (CT scan, 25%), and 62.5% for tumoral lymph nodes (CT scan, 0%). The specificity of all techniques was excellent. Correct diagnosis was made by endoscopic ultrasonography alone in 41% of the patients. The combination of conventional endoscopy and endoscopic ultrasonography provided correct diagnosis in 60% of the patients.

CONCLUSIONS: Endoscopic ultrasonography should be considered as a first-choice imaging technique for preoperative detection of gastrinomas. Although small duodenal gastrinomas are still obviously difficult to detect, an accurate exploration of the pancreatic area was provided by this technique.