Zollinger-Ellison syndrome

Zollinger–Ellison syndrome (ZES) is a disease in which tumors cause the stomach to produce too much acid, resulting in peptic ulcers. Symptoms include abdominal pain and diarrhea. Zollinger–Ellison syndrome (ZES) is a disease in which tumors cause the stomach to produce too much acid, resulting in peptic ulcers. Symptoms include abdominal pain and diarrhea. The syndrome is caused by a gastrinoma, a neuroendocrine tumor that secretes a hormone called gastrin. The tumor causes excessive production of gastric acid, which leads to the growth of gastric mucosa and proliferation of parietal and ECL cells. ZES may occur on its own or as part of an autosomal dominant syndrome called multiple endocrine neoplasia type 1 (MEN 1). The primary tumor is usually located in the pancreas, duodenum or abdominal lymph nodes, but ectopic locations (e.g., heart, ovary, gallbladder, liver, and kidney) have also been described. Patients with Zollinger–Ellison syndrome may experience abdominal pain and diarrhea. The diagnosis is also suspected in patients who have severe ulceration of the stomach and small bowel, especially if they fail to respond to treatment. Gastrinomas may occur as single tumors or as multiple small tumors. About one-half to two-thirds of single gastrinomas are malignant tumors that most commonly spread to the liver and to lymph nodes near the pancreas and small bowel. Nearly 25 percent of patients with gastrinomas have multiple tumors as part of a condition called multiple endocrine neoplasia type 1 (MEN 1). MEN I patients have tumors in their pituitary gland and parathyroid glands, in addition to tumors of the pancreas. Gastrin works on the parietal cells of the gastric glands, causing them to secrete more hydrogen ions into the stomach lumen. In addition, gastrin acts as a trophic factor for parietal cells, causing parietal cell hyperplasia. Thus, there is an increase in the number of acid-secreting cells, and each of these cells produces acid at a higher rate. The increase in acidity contributes to the development of peptic ulcers in the stomach, duodenum (first portion of the small bowel) and occasionally the jejunum (second portion of the small bowel)-- the last of which is an 'atypical' ulcer. Zollinger–Ellison syndrome may be suspected when the above symptoms prove resistant to treatment, when the symptoms are especially suggestive of the syndrome, or when endoscopy is suggestive. The diagnosis is made through several laboratory tests and imaging studies: In addition, the source of the increased gastrin production must be determined using MRI or somatostatin receptor scintigraphy.