Dual-phase multidetector thin-section CT in detecting duodenal gastrinoma.

Preoperative localization of gastrinomas, especially of extrapancreatic origin, remains a challenge to the radiologist. Most patients with extrapancreatic gastrinomas undergo surgery without preoperative identification of the primary tumor. The appropriate imaging modality to localize gastrinomas is under continuing debate. We report a case of a duodenal gastrinoma with regional lymph node metastases that presented with Zollinger-Ellison syndrome. The small primary tumor was detected noninvasively by dual-phase multidetector thin-section computed tomography with adequate bowel distention and confirmed by endoscopy and histopathologic examination. The case illustrates that appropriate computed tomographic technique and scanning protocol are crucial for success in localizing extrapancreatic gastrinoma.