This is a rare disease caused by overproduction of gastrin by G cell tumours of the pancreas or the duodenum. Maximal stimulation of the parietal cells leads to intractable peptic ulcerations. Ninety per cent of gastrinomas occur within the ‘gastrinoma triangle’ bounded by the cystic duct and bile duct, the junction of the head and neck of the pancreas, and the second and third parts of the duodenum. Two-thirds of all gastrinomas
occur outside the pancreas. More than 60% of gastrinomas are malignant. Twenty per cent of patients with Zollinger–Ellison syndrome have micro-adenomatosis of the pancreas rather than discrete tumours.
The diagnosis should be suspected when peptic ulcers occur at unusual sites, such as the second part of the duodenum or the jejunum, or ulcers recur after adequate surgery. One-third of patients have watery diarrhea due to high gastric output. Dehydration, and acid–base or electrolyte imbalance may occur.
Measurement of gastric acid output Because of the high circulating gastrin, the basal acid output (BAO) is high and stimulation with pentagastrin does not elicit significant increase. A BAO of more than 15 mmol/h and a BAO to maximal acid output ratio
(BAO : MAO) of more than 0.6 is highly suggestive.
The aim of treatment of Zollinger–Ellison syndrome is two-fold:
To control the high gastric acid output and sever the ulcer diathesis
To treat the gastrinoma In the past a total gastrectomy was recommended to Remove gastric acid production. Nowadays, the ulcer diathesis can usually be controlled by an adequate dose of omeprazole. If a single discrete tumour can be identified in the pancreas or the duodenum, surgical excision is the treatment of choice.