Gastrinomas

Zollinger-Ellison syndrome (ZES) is characterized by the development of a tumor (gastrinoma) or tumors that secrete excessive levels of gastrin, a hormone that stimulates production of acid by the stomach. In most cases, the tumor or tumors arise within the pancreas and/or the upper region of the small intestine (duodenum). 

Less common causes of peptic ulceration include Zollinger-Ellison syndrome (ZES), cancer chemotherapy, radiation, and vascular insufficiency. ZES is caused by a gastrin-producing tumor called a gastrinoma and results in gastric acid hypersecretion. High-dose oral proton pump inhibitor (PPI) therapy is the initial treatment of choice for ZES intermittent intravenous PPI therapy may be required for any patient in whom oral therapy is contraindicated.1... 

The answers are 406-c, 407-g. (Hardman, pp 907—9097 926-927.) Omeprazole, which is an inhibitor of the parietal cell H+,lC,ATPase pump (proton pump), is the most effective means of decreasing gastric acidity This makes it the ideal agent to treat Zollinger-Ellis on syndrome, which results from increased gastric secretion due to gastrinomas. 

Sustained acid hyperscretion, due either (usually) to a duodenal or pancreatic gastrinoma, or to multiple endocrine adenomata, responds well to proton pump inhibition, often requiring high doses. Resection should always be considered as a cure for those with solitary adenomata, as should operation to reverse the retained antrum syndrome (partial gastrectomy where the antrum is inadvertently retained and isolated from acid inhibition, and secretes gastrin continuously). 

Shojamanesh H, Gibril F, Louie A, Ojeaburu JV, Bashir S, Abou-Saif A, Jensen RT. Prospective study of the antitumor efficacy of long-term octreotide treatment in patients with progressive metastatic gastrinoma. Cancer 2002 94(2) 331 13. 

Zollinger-Ellison syndrome is characterised by increased levels of the hormone gastrin, causing the stomach to produce excess hydrochloric acid. Often the canse is a tnmonr (gastrinoma) of the duodenum or pancreas. Peptic ulcers occur in almost 95% of patients. 

Ko TC, Flisak M, Prinz RA. Selective intra-arterial methylene blue injection a novel method of localizing gastrinoma. Gastroenterology 1992 102(3) 1062-4. 

Indications Diagnosis of gastrinoma (Zollinger-Ellison syndrome)... 

A level of free acid >15 mmol/hr should prompt a suspicion of gastrinoma but is not diagnostic a level >25 mmol/hr with high serum gastrin is virtually diagnostic of Zollinger-Ellison syndrome. 

NEUROENDOCRINE TUMORS Gastrinoma and the Zollinger-Ellison SYNDROME ... 

Hormone secreting tumors (VlPoma, gastrinoma, carcinoid) Other ... 

Goetze JP, Rehfeld JF. Impact of assay epitope specificity in gastrinoma diagnosis. Clin Chem 2003 49 333-4. 

Jensen RT. Gastrinoma. In O Shea D, Bloom SR, eds. BaElieres clinical gastroenterology. London BaEfiere Tindall, 1996 10 603-43. 

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