Detection of a Small Gastrinoma by Combined Radiologic and Scintigraphic Techniques

The aim of this study was to improve the localization of somatostatin receptor positive gastroenteropancreatic neuroendocrine neoplasias. Of this group, gastrinomas are well known to display a high density of somatostatin II receptors. Therefore, the sensitivity and specificity of scintigraphic tumor visualization is very high. Because the primary sites and the metastatic spread vary considerably, exact preoperative localization demands additional anatomical information. A 65-year-old man with clinical symptoms of the Zollinger-Ellison syndrome showed an eight-fold elevated serum gastrin concentration. After assessment of the gastrinoma by somatostatin receptor scintigraphy in the right upper abdominal quadrant, a nasoduodenal tube was labeled and used as a landmark, followed by double-contrast radiographs, visualizing the lesion, the tube, and the gastroduodenal anatomy. Additionally, transaxial SPECT images superimposed on corresponding CT slices revealed a singular lesion at the pyloric region. A tumor of 0.2 mL was completely removed by Billroth's-I resection. In preoperative localization, the combination of scintigraphic and topographic methods improves the meaning of receptor scintigraphy. For very small single lesions, surgical resection can be restricted to the adequate minimum.