In patients with ZES and proved or suspected MEN I, serum calcium and parathyroid hormone levels often may be elevated. If hyperparathyroidism is present, it should be treated initially or concurrently because calcium potentiates gastrin secretion. Initial treatment of ZES is often pharmacologic, consisting of proton pump inhibiters. Although these may control symptoms and prevent sequelae of ulcer disease, they do not address tumor behavior or the malignant potential. If surgical resection is possible, it is often recommended to prevent tumor spread and to provide a long-term cure. Application of this principle in patients with MEN I is more contentious because localization is more difficult and multifocal disease is common. Preoperative tumor localization often includes somatostatin receptor scintigraphy and CT to evaluate the pancreas, peripancreatic lymph nodes, and potential liver metastases.2,3Endoscopic ultrasonography is used in some centers to identify occult primary lesions. Imaging of small duodenal gastrinomas with any of these techniques is exceptionally rare.