The duodenum is the top part of the small intestine. The tumors are cancerous in 50 percent of cases. The ulcers caused by Zollinger-Ellison syndrome are more painful and less responsive to treatment than ordinary peptic ulcers. What causes people with Zollinger-Ellison syndrome to develop tumors is unknown, but the cause may be an abnormal tumor suppressor gene. Zollinger-Ellison syndrome usually occurs in people between ages 30 and 60.
Diarrhea is also a symptom.
Physicians diagnose Zollinger-Ellison syndrome through blood tests to measure levels of gastrin. They may check for ulcers by taking x-rays of the stomach and duodenum or by doing an endoscopy, which involves looking at the lining of these organs through a lighted tube. Medications used to reduce stomach acid include cimetidine, ranitidine, famotidine, and omeprazole. Surgery to treat peptic ulcers or to remove tumors in the pancreas or duodenum are other treatment options. In serious cases, surgery to remove the entire stomach may be necessary.