Zollinger-Ellison Syndrome

– A syndrome marked by hypergastrinemia, gastric acid hypersecretion, and recurrent peptic ulcerations.

Causes and Incidence

The cause of Zollinger-Ellison syndrome (ZES) is excessive gastrin secretion produced by a non-beta islet cell tumor in the pancreas. Most individuals have several tumors, and about 50% of the tumors are malignant. ZES often occurs in conjunction with other endocrine abnormalities, particularly of the parathyroids. About 60% of cases are seen in men. The peak incidence occurs between 30 and 50 years of age.

Disease Process

The high serum gastrin levels continuously stimulate HCl hypersecretion from parietal cells. This constant production of HCl overcomes the duodenum’s ability to neutralize the acid, and peptic ulcers result. The gastrin stimulates intestinal motility and increases secretion of water and electrolytes, and the HCl increases peristalsis. Intestinal pH and fat breakdown are diminished, which inactivates pancreatic lipase and interferes with absorption of a variety of substances in the intestine. Gastrin also stimulates intrinsic factor secretion and interferes with vitamin B12 absorption.

Symptoms

The major manifestations stem from peptic ulcer formation and include burning epigastric pain that is relieved by food and coffee ground or bloody emesis. Diarrhea, steatorrhea, foul-smelling stools, anorexia, and weight loss may also be present.

Potential Complications

The mortality rate is high because of malignant metastasis to the liver, spleen, bone, skin, and peritoneum and perforation and hemorrhage of the peptic ulcers.

Diagnostic Tests

Serum gastrin
Elevated to 500 pg/ml or higher.

Endoscopy/x-ray
To detect ulcers.

Provocative tests
Serum gastrin rises within 30 minutes of injection of secretin and calcium.

Arteriography
To locate pancreatic tumors.

Treatments

Surgery
Resection of tumor possible in 20% of cases; total gastrectomy when ulcers are not responding to medication.

Drugs
Histamine-receptor antagonists to reduce gastric acid output; antacids to relieve pain; anticholinergics in refractory cases; omeprazole or octreotide to reduce gastric acid when resistance to histaminereceptor antagonists develops; chemotherapy to treat malignant tumors; vitamin B12 injections, iron and calcium supplements.

General
Fluid replacement with diarrhea; monitoring for dehydration and electrolyte imbalance; support to aid in adaptation.