Causes, symptoms, diagnosis and treatment of Zollinger-Ellison syndrome

What are gastrinomas and Zollinger-Ellison syndrome (ZES)?

A gastrinoma is a special neuroendocrine tumor that produces large amounts of gastrin. Zollinger-Ellison syndrome (ZES) is a disorder characterized by the presence of a gastrinoma in the duodenum or pancreas, hypergastrinemia and ulcers in the upper gastrointestinal tract.

Epidemiology of gastrinomas: how common are they?

Although gastrinomas are rather rare, they are one of the more common functionally active tumors. The incidence is about 1-5 cases per 1 million people per year. In patients with duodenal ulcer, the prevalence of gastrinomas is about 0.1%. Sporadic gastrinomas typically occur in the fifth decade of life, while MEN1-associated gastrinomas usually occur somewhat earlier. Women are slightly more likely to develop ZES than men.

Causes of gastrinomas: sporadic or as part of MEN1?

In most cases (75%), Zollinger-Ellison syndrome occurs sporadically, while in 25% of cases it occurs as part of MEN1 syndrome. MEN1 syndrome is a hereditary disease that can lead to various tumors, including gastrinomas. These tumors develop from pluripotent stem cells of the enteropancreatic system and are usually well differentiated histologically.

Pathogenesis of gastrinomas: how do they develop and what are their consequences?

Gastrinomas develop from stem cells of the digestive tract and lead to excessive production of gastrin. This hormone stimulates gastric acid production and can lead to ulcers. Chronic hypersecretion of gastric acid can lead to gastrointestinal complications such as diarrhea and malabsorption.

Symptoms of gastrinomas and ZES: How does the disease manifest itself?

The symptoms of ZES are varied and include abdominal pain, diarrhea, steatorrhea, gastroesophageal reflux, nausea and vomiting. If left untreated, the disease can lead to serious complications such as upper gastrointestinal bleeding and perforation.

Diagnosis of gastrinomas and ZES: How is the disease diagnosed?

ZES is diagnosed by detecting elevated fasting gastrin levels in the serum in combination with a reduced gastric juice pH. Further examinations such as the secretin test and the determination of marker proteins such as chromogranin A and synaptophysin can help to confirm the diagnosis.

Treatment of gastrinomas and ZES: What treatment options are there?

The treatment of ZES is primarily aimed at alleviating the symptoms and reducing gastric acid production. This is achieved by administering proton pump inhibitors (PPI) or H2 blockers. In sporadic gastrinomas, endoscopic or surgical resection of the tumor may also be necessary. Chemotherapy or the administration of somatostatin analogs may be considered for metastatic tumors.

Prognosis of gastrinomas and ZES: What is the long-term outlook?

The prognosis of gastrinomas depends largely on whether the tumor is already metastatic at the time of diagnosis. Non-metastatic gastrinomas have a good prognosis, while metastatic gastrinomas are associated with a lower survival rate.

Notes and recommendations: Important information on gastrinomas and ZES

There are certain guidelines that should be followed in the treatment of ZES, e.g. avoidance of ranitidine due to safety concerns. Genetic counseling is also recommended for patients with MEN1.

Conclusion

Gastrinomas and Zollinger-Ellison syndrome are complex diseases that require careful diagnosis and treatment. With timely and appropriate treatment, the prognosis can be improved. If ZES is suspected, it is important to consult a specialist in order to receive the best possible care.