Overview
Zollinger-Ellison syndrome (ZES) is an endocrinopathy caused by gastrin-secreting tumours which cause the stomach to produce excess acid, leading to multiple and recurrent peptic ulcers. The tumours usually occur in the duodenum or pancreas. ZES is associated with multiple endocrine neoplasia type 1 (MEN 1) in around 30% of cases.
Epidemiology
- ZES is rare, with an incidence of up to 2 per 1,000,000 per year
- The mean age of presentation is around 40 years, this may be lower in patients with MEN1
Presentation
Patients present with recurrent and/or refractory peptic ulcers and ZES is often treated as simple peptic ulcers. Features include:
- Epigastric pain – due to peptic ulcers, often described as burning
- Gastro-oesophageal reflux disease
- Gastrointestinal bleeding
- Diarrhoea – peptic ulcer disease and diarrhoea suggests ZES
Investigations
Overview
- Fasting serum gastrin:
- Used as initial screening and is increased due to tumour production
- Secretin stimulation test:
- Secretin normally inhibits gastrin release, however, gastrinoma cells release gastrin in response to secretin
- Upper gastrointestinal endoscopy:
- May identify peptic ulcers
- Endoscopic ultrasound:
- May identify ulcers
Other tests
If ZES is confirmed, tests for MEN1 should be considered:
- Serum calcium:
- May be elevated
- Serum parathyroid hormone (PTH):
- May be elevated
- Serum prolactin:
- May be elevated
Management
Management involves the use of proton pump inhibitors (e.g. omeprazole) and H2-receptor antagonists to suppress acid secretion and surgical resection.
Complications
- Peptic ulcer bleeding and perforation
- Metastatic gastrinoma
- Metastases usually spread to the liver and bone
Prognosis
- Most patients with ZES require continuous PPI treatment and have lifelong increased serum gastrin
- The prognosis is poorer in patients with metastatic disease and markedly increased fasting gastrin levels
