Patients with<unk>  may experience abdominal pain and diarrhea. The diagnosis is also suspected in patients without symptoms 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 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 I (MEN I). MEN I patients have tumors in their pituitary gland and parathyroid glands in addition to tumors of the pancreas. Development of<unk>  is the result of increased levels of gastrin due to an existing gastrinoma in the duodenum or pancreas.<unk>  must be differentiated from gastric antrum<unk> , antral G-cell hyperplasia, peptic ulcer, gastroesophageal reflux disease (GERD), and hypergastrinemia. The incidence of gastrinoma, which can cause<unk> , is approximately 0.5-2 persons per 100,000 individuals worldwide. Pharmacologic medical therapies for<unk>  include proton pump inhibitors, H2-receptor antagonists, chemotherapy, and hormonal therapy. Effective measures for the primary prevention of<unk>  include genetic testing, if family history presents.
Zollinger-Ellison syndrome
Johanson-Blizzard syndrome
Whipple's disease
Hereditary pancreatitis
Lucey-Driscoll syndrome
Zieve's syndrome
Bloom syndrome
Vacinko syndrome