What Is Zollinger-Ellison Syndrome?

Zollinger-Ellison syndrome (ZES) is a digestive disorder that occurs when tumors called gastrinomas form in the pancreas or duodenum (the first part of the small intestine). Gastrinomas are tumors that produce a large amount of gastrin—a hormone that causes your body to produce more stomach acid. People with ZES have an excessive amount of stomach acid and experience symptoms similar to peptic ulcer disease and gastroesophageal reflux disease (GERD). 

Zollinger-Ellison syndrome is rare and affects about up to three out of every one million people in the United States. If you have this condition, it's important to know that 50-67% of gastrinomas turn out to be cancerous. Fortunately, treatment is available to manage the condition well.

Zollinger-Ellison Syndrome Symptoms 

People with Zollinger-Ellison syndrome have extra stomach acid in their digestive tracts. This excessive amount of acid can lead to several common symptoms including:

• Diarrhea
• Heartburn or burning in your chest 
• Abdominal pain
  
• Nausea and vomiting
• Unintentional weight loss

ZES may also cause more serious symptoms, especially if the condition is left untreated. See your healthcare provider if you develop any of the following signs or symptoms: 

• Chest pain
• Persistent vomiting
• Trouble breathing
• Difficulty swallowing food
• Bleeding in the digestive tract 
• Sudden or sharp stomach pain
• Muscle weakness
• Lightheadedness 
• Fatigue

Causes

Zollinger-Ellison syndrome occurs when tumors called gastrinomas form in the pancreas or duodenum. Researchers are still investigating what exactly causes gastinomas to form. Gastrinomas release large amounts of the hormone gastrin. Normally the body releases a small amount of gastrin after you eat. This leads to a small amount of stomach acid to help digest your food. However, too much gastrin leads to too much stomach acid, which can increase your risk of this condition.

While research is ongoing, experts theorize that about 20-25% of cases of Zollinger-Ellison syndrome are a result of a rare genetic disorder called multiple endocrine neoplasia type 1 (MEN1). This may indicate that there are genetic factors involved in the development of this disease.

Risk Factors

Certain factors can also raise your risk of developing gastrinomas. The current risk factors for ZES include:

• Being between ages 20-50
• Being assigned male at birth
• Having a family history of multiple endocrine neoplasia type 1 (MEN1) 

Diagnosis

If you have developed symptoms of Zollinger-Ellison syndrome, it's important to see your primary healthcare provider for proper testing and treatment. If your provider suspects you have ZES or a similar digestive condition, they will likely refer you to a gastroenterologist (a doctor who specializes in digestive disorders).

Your provider will start the diagnostic (testing) process with a physical exam and medical history. They will ask several questions about your symptoms including when they started, what makes them worse, and how they affect your daily life. Your provider will also ask about your family’s health history. Once they learn more information about your symptoms and background, they will likely check for physical symptoms like abdominal pain or changes in weight.

Taking your medical history and performing a physical exam usually isn't enough to make a diagnosis for ZES. That said, you can expect your provider to order one or more of the following tests:

• Gastrin blood test: Tests your gastrin level by administering intravenous (IV) secretin, a hormone that causes gastrinomas to produce gastrin. If your gastrin levels are very high, you likely have Zollinger-Ellison syndrome. 
• Stomach acid tests: Assesses the pH (acidity) of your stomach fluids by inserting a tube through your nose, down your throat, and into the stomach. 
• Upper GI endoscopy: The provider inserts a flexible tube with a camera called an endoscope down your throat to check the lining of the upper gastrointestinal (GI) tract for tumors. 
• Endoscopic retrograde cholangiopancreatography (ERCP): Combines an upper GI endoscopy with X-rays to examine the bile ducts and pancreatic ducts for tumors. 
• Computed tomography (CT) scan: Uses a combination of X-rays and computer technology to create images of the pancreas and small intestine.
• Magnetic resonance imaging (MRI): Takes detailed X-rays of the pancreas and small intestine from multiple angles to check for inflammation, tumors, and other abnormalities.
• Radionuclide scanning: Injects a small amount of radioactive material into your body, then uses a special camera to take images that highlight the radioactive material in any gastrinomas you may have.
• Endoscopic ultrasound: Involves using an endoscope with ultrasound technology to examine the pancreas and small intestine.
• Angiography: Creates X-ray images by threading a catheter through large arteries to inject a special dye and check for abnormalities.
  

Treatments for Zollinger-Ellison Syndrome  

Unfortunately, there isn't a cure for Zollinger-Ellison syndrome at this time. However, treatment can help control symptoms of ZES.

Medications

Proton pump inhibitors (PPIs) are medications that help lower the amount of acid that the stomach makes. Your provider may recommend a PPI to relieve your symptoms and heal your gastrointestinal tissues. Many people with Zollinger-Ellison syndrome need to take PPIs for the rest of their lives. Fortunately, these medications are generally considered safe and effective. Common medications include Protonix (pantoprazole) and Prilosec (omeprazole). 

However, these medications don't come without side effects, which include:

• Headache
• Diarrhea
• Upset stomach
• Low vitamin B12 levels 

While less commonly used, H2 blockers are another medication that lowers the amount of acid produced in the stomach. Examples of this medicine include Tagamet (cimetidine) and Zantac (ranitidine). 

Surgery

In some cases, a surgeon can help significantly improve Zollinger-Ellison syndrome symptoms by removing the tumors. This surgery is not an option for people with MEN1. If you are eligible for this surgery, it may be necessary to take PPIs after the procedure to control the amount of stomach acid. 

Prevention

Unfortunately, it's not usually possible to prevent Zollinger-Ellison syndrome. This is because researchers are not certain why gastrinomas form, therefore, proper prevention methods haven't been understood yet.

To lower your risk of experiencing severe symptoms, talk with your healthcare provider about a treatment plan as soon as you have symptoms. Taking your medications as prescribed and adjusting your treatment if needed can be effective in keeping symptoms at bay.

Related Conditions 

Zollinger-Ellison syndrome is a chronic (long-term) condition and may raise the risk of other health problems over time. Possible complications of Zollinger-Ellison syndrome include:

• Peptic ulcer disease
• Gastroesophageal reflux disease (GERD)
• Bleeding in the upper digestive tract
• Perforation (holes) in the digestive tissue
• Blockages in the stomach, making it difficult for food to pass through the digestive tract
• Cancer

Living With Zollinger-Ellison Syndrome

For most people, Zollinger-Ellison syndrome is a lifelong condition. It is important to see your gastroenterologist regularly so they can help you monitor your symptoms. If you have this condition, taking your medication exactly as prescribed can help keep symptoms at a minimum.

Because up to two-thirds of gastrinomas are cancerous, it's important to see your provider if you develop heartburn or chronic diarrhea. In most cases, the earlier cancer is diagnosed, the more treatable it is.