What is the cause of Zollinger-Ellison syndrome?

Having good health is indeed a blessing. When a person falls sick, they may end up not being able to become productive and being sick for a long period of time not only causes emotional distress but also financial issues. Thus, getting regular health screening can be very helpful in detecting diseases that can be prevented or treated early. This is very true for one of the many diseases that can be detected through health screening known as Zollinger-Ellison syndrome.

Zollinger-Ellison syndrome is a rare condition that occurs when one or more tumours known as gastrinoma lead to overproduction of acid in the stomach. Gastrinoma typically located in the pancreas or duodenum. Gastrinomas can occur as a single or several ones. One half to two thirds of single gastrinomas are cancerous as it often spreads to the liver and nearby lymph nodes. 25% of people with gastrinomas have several tumours as part of a condition known as multiple endocrine neoplasia type 1 (MEN1). MEN1 is a group of hyperplastic cells and/or tumours of the pituitary, parathyroid and pancreas cells.

In normal people, gastrin is released in small amounts after eating. Gastrin triggers the stomach to produce stomach acid that helps to break down food and aids in digestion. Gastrinomas release large amounts of gastrins that stimulate the production of excessive stomach acid. In most cases of Zollinder-Ellison syndrome, it is not known what causes gastrinomas to form.

Common symptoms include abdominal pain, diarrhoea and heartburn which are caused by excess gastrin from gastrinomas. Patients may present with long periods of persistent symptoms before Zollinger-Ellison syndrome can be suspected. Patients may be presented with weight loss and chronic diarrhoea due to malabsorption caused by the excessive stomach acid production.

One of the way that doctor are able to suspect Zollinger-Ellison syndrome is when patient still have symptoms despite taking proton pump inhibitor (PPI) medication. PPI medication should be able to reduce excessive stomach acid in many conditions but not in Zollinger-Ellison syndrome. Another clue to Zollinger-Ellison syndrome should be suspected is when there is family history of endocrinopathy or some history of refractory of peptic ulcer disease at an early stage. Endocrinopathy includes hypercalcemia (high level of calcium in blood) and kidney stones from parathyroid hyperplasia and/or neoplasm. Last but not least, doctors often suspect the syndrome if there is presence of peptic ulcer disease without the presence of Helicobacter pylori (H. pylori) infection or without history of nonsteroidal anti-inflammatory drug (NSAID).

Once a person is suspected with Zollinger-Ellison syndrome, doctors will run further tests to confirm it. This includes blood tests to check for gastrin levels in blood, checking for the acidity of pH of the stomach fluids, measuring amount of stomach acid, and imaging tests such as endoscopy to evaluate the upper gastrointestinal tract and CT or MRI scan. Checking for gastrin levels In blood usually needs a patient to fast for several hours and only allowed to drink water. Doctors may order another blood test to check for gastrin levels after receiving secretin through the vein (intravenous secretin). High levels of gastrin could be a sign of Zollinger-syndrome. Imaging tests help to identify the tumour and to check for possibility if it has been spread. Screening for MEN1 may also be done.

Treatment will depend on the severity of the disease. In most cases, PPI is given to help lower the amount of acid produced by the stomach. This also helps the ulcer in the stomach or small intestine to heal apart from relieving abdominal pain and diarrhoea. Doctors may recommend surgery to remove tumours that cause Zollinger-Ellison syndrome in those without MEN1. In some cases, removal of the gastrinomas can cure Zollinger-Ellison syndrome. This also prevents the tumour from spreading to other parts of the body. People may still need to take PPIs to control stomach acid following surgery. Surgery is typically not recommended in those with MEN1. Those with MEN1 often have gastrinomas that are small and have many small tumours. This makes it difficult for surgeons to completely remove all of it. Doctors may recommend surgery to remove larger tumours as this kind of tumour has a higher chance of spreading. In case of gastrinomas that are cancerous or have spread, doctors may recommend chemotherapy or other cancer treatment.

It can be concluded that Zollinger-Ellison syndrome is a rare condition that is caused by gastrinomas that produce excessive stomach acid. Symptoms such as heartburn, diarrhoea and abdominal pain often mimic other conditions associated with excessive stomach acid. It is best to get checked by a doctor whenever symptoms persist despite taking medications to try to alleviate symptoms. Treatment can be PPI medicine or surgery, depending on the severity of the disease. Although gastrinoma does sound scary as tumours often sound bad, it grows slowly and many people with this condition do live for many years even after the tumour is found.