Zollinger-Ellison syndrome is a condition that occurs with abnormal production of the hormone gastrin. A small tumor (gastrinoma) in the pancreas or small intestine produces the high levels of gastrin in the blood.

Zollinger-Ellison syndrome is caused by tumors, usually found in the head of the pancreas and the upper small bowel. These tumors produce the hormone gastrin and are called gastrinomas. High levels of gastrin cause too much production of stomach acid.

Gastrinomas occur as single tumors or as small, multiple tumors. About one-half to two-thirds of single gastrinomas are cancerous (malignant) tumors that commonly spread to the liver and nearby lymph nodes.

A number of patients with gastrinomas have many tumors as part of a condition called multiple endocrine neoplasia type I (MEN I). MEN I patients often have tumors of the pituitary gland (brain) and parathyroid gland (neck), as well as tumors of the pancreas.

• Abdominal pain
• Diarrhea
• Ulcers in the stomach and small bowel
• Vomiting blood (occasional)

• Abdominal CT scan
• Calcium infusion test
• Endoscopic ultrasound
• Exploratory surgery
• Elevated gastrin level
• Octreotide scan
• Secretin stimulation test

Medications called proton pump inhibitors (omeprazole, lansoprazole) are now the first choice for treating Zollinger-Ellison syndrome. These drugs reduce acid production by the stomach, and promote healing of ulcers in the stomach and small bowel. They also relieve abdominal pain and diarrhea.

Surgery to remove a single gastrinoma may be done if there is no evidence that it has spread to other organs (such as lymph nodes or the liver). Surgery on the stomach (gastrectomy) to control acid production is rarely needed today.

Even with early diagnosis and surgery to remove the tumor, the cure rate is relatively low. However, gastrinomas grow slowly, and patients may live for many years after the tumor is discovered. Acid-suppressing medications are very effective at controlling the symptoms of too much acid production.

• Failure to locate the tumor during surgery
• Intestinal bleeding or hole (perforation) from ulcers in the stomach or duodenum
• Severe diarrhea and weight loss
• Spread of the tumor to other organs (most often liver and lymph nodes)

Call your health care provider if you have severe abdominal pain that does not go away, especially if it occurs with diarrhea.