Chapter 115 - Zollinger-Ellison Syndrome

Abstract

Gastrinoma is a neuroendocrine tumor (NET) that secretes gastrin and may occur as a sporadic or inherited disease (as part of multiple endocrine neoplasia type 1 [MEN1]). Virtually all medical complications associated with the elevated gastrin serum levels can be treated medically using proton pump inhibitors. All patients with sporadic gastrinomas should have the tumor resected if possible, and most patients with MEN1-associated gastrinoma should have medical therapy unless they develop metastasis or locally invasive tumors. Preoperative localization studies should include thin-cut computed tomography (CT) scan, endoscopy, endoscopic ultrasound, and 68-gallium DOTA peptide analogs to properly localize and stage the patient. Even if all localizing studies are negative and a patient has biochemical evidence of a sporadic gastrinoma, surgical exploration with a duodenotomy and intraoperative ultrasound of the pancreas and bimanual palpation localizes most lesions. Surgical treatment for sporadic gastrinoma is associated with improved survival. Patients with isolated liver metastasis may benefit from hepatectomy or local ablative procedures or embolization. Patients with widely metastatic or unresectable gastrinoma may be treated with somatostatin analogs, targeted agents such as sunitinib and everolimus, and/or peptide receptor radionucleotide therapy; all of these treatments have been associated with prolonged progression-free survival.