Zollinger-Ellison Syndrome Causes, SYmptoms, Diagnosis, Treatment, Prevention

Zollinger-Ellison Syndrome Causes, SYmptoms, Diagnosis, Treatment, Prevention

What is Zollinger-Ellison Syndrome?

Zollinger-Ellison Syndrome is a rare disorder that causes one or more tumors to form in the pancreas or the upper part of the small intestine called the duodenum. It can also cause ulcers to develop in the stomach and the duodenum.

The tumors are called gastrinomas, and they secrete a large amount of the hormone gastrin. This then causes an excessive production of stomach acid, which can lead to peptic ulcers.

Zollinger-Ellison syndrome is rare, and though it may occur at any age, people between the ages of 30 and 60 are more likely to develop it. Also, of all the people who suffer with a peptic ulcer, only a tiny percentage of those people will have Zollinger-Ellison.

The tumors are cancerous in 50 percent of the cases. They secrete a hormone called gastrin that causes the stomach to produce too much acid, which in turn causes stomach and duodenal ulcers (peptic ulcers). The ulcers caused by Zollinger-Ellison Syndrome are less responsive to treatment than ordinary peptic ulcers. What causes people with Zollinger-Ellison Syndrome to develop tumors is unknown, but approximately 25 percent of Zollinger-Ellison Syndrome cases are associated with a genetic disorder called multiple endocrine neoplasia.

Causes of Zollinger-Ellison Syndrome

The exact cause of Zollinger-Ellison syndrome remains unknown. But the sequence of events that occurs in Zollinger-Ellison syndrome is clear. The syndrome begins when a tumor (gastrinoma) or tumors form in your pancreas, duodenum or the lymph nodes adjacent to your pancreas.

Your pancreas sits behind and below your stomach. It produces enzymes that are essential to digesting food. The pancreas also produces several hormones, including gastrin, a hormone that controls stomach acid production. Digestive juices from the pancreas, liver and gallbladder mix in the duodenum, the part of the small intestine next to your stomach. This is where digestion reaches its peak.

The tumors that occur with Zollinger-Ellison syndrome are made up of cells that secrete large amounts of gastrin, which in turn causes the stomach to produce far too much acid. The excessive acid then leads to peptic ulcers and sometimes to diarrhea.

Besides causing excess acid production, the tumors may be cancerous (malignant). The tumors themselves grow slowly, but the cancer can spread elsewhere — most commonly to nearby lymph nodes or your liver.

Association with MEN I 

Zollinger-Ellison syndrome may be caused by an inherited condition called multiple endocrine neoplasia, type I (MEN I). People with MEN I have multiple tumors in the endocrine system in addition to pancreatic tumors. They also have tumors in the parathyroid glands and may have tumors in their pituitary glands. About 25 percent of people who have gastrinomas have them as part of MEN I.

Symptoms of Zollinger-Ellison Syndrome

  • Gnawing, burning pain in the abdomen
  • This pain is usually located in the area between the breastbone and the navel.
  • Sensation of pressure, bloating, or fullness
  • This pain usually develops 30 to 90 minutes after a meal, and is often relieved by antacids.
  • Pain or burning sensation in the abdomen that travels up toward the throat
  • This is caused by heartburn, or gastroesophageal reflux, and occurs when stomach contents back up into the esophagus.
  • Vomiting
  • The vomit may contain blood or resemble coffee grounds.
  • Diarrhea
  • Stools may be foul smelling.
  • Black, tarry stools
  • Blood in the stools will turn them dark red or black, and make them tarry or sticky.
  • Nausea
  • Fatigue
  • Weakness
  • Weight loss
  • Anemia

When to see a doctor 

See your doctor if you have a persistent, burning, aching or gnawing pain in your upper abdomen, especially if you've also been experiencing nausea, vomiting and diarrhea.

Tell your doctor if you've used over-the-counter acid-reducing medications such as omeprazole (Prilosec), cimetidine (Tagamet), famotidine (Pepcid) or ranitidine (Zantac) for long periods of time. These medications may mask your symptoms, which could delay your diagnosis. If you have Zollinger-Ellison syndrome, early detection and treatment are important.

Complications of Zollinger-Ellison Syndrome

In 50 percent of cases of Zollinger-Ellison, the tumors are cancerous (malignant). If the tumors are cancerous, there is a risk that the cancer will spread to the liver, the lymph nodes near the pancreas and small intestine.

Other Complication of Zollinger-Ellison Syndrome

  • Severe ulcers that may lead to the development of a hole in the bowel
  • Blood loss
  • Chronic diarrhea
  • Weight loss

How to Diagnose Zollinger-Ellison Syndrome

Your doctor will ask about your symptoms and medical history, and perform a physical exam. He or she may also refer you to a gastroenterologist, a specialist who deals with gastrointestinal disorders.

Tests may include the following:

Gastrin stimulation tests
  • Standard test meal
  • Calcium
  • Secretin ( a hormone)
Blood tests
  • Looking for elevated gastrin levels in blood
  • Abdominal computerized tomography (CT) scan or magnetic resonance imaging (MRI) of the abdomen to show tumors
  • Abdominal ultrasound
Upper gastrointestinal endoscopy
  • A thin instrument with a light and camera is inserted down the throat and into the stomach and intestine to look for ulcers

Treatment of Zollinger-Ellison Syndrome

The treatment of Zollinger-Ellison syndrome focuses on two areas: Treating the tumors and treating the ulcers.

Treatment for tumors in Zollinger-Ellison Syndrome

Surgery is often performed if there is only one tumor. If tumors are in the liver, a surgeon will remove as much of a liver tumor as possible (debulking).

When surgery on tumors isn't possible, other treatments are used:

  • Attempting to destroy the tumor by cutting off the blood supply (embolization).
  • Attempting to destroy cancer cells by using an electric current (radio-frequency ablation).
  • Injecting drugs into the tumor to relieve cancer symptoms.
  • Using chemotherapy to try to slow tumor growth.

Treatment for ulcers in Zollinger-Ellison Syndrome

Proton pump inhibitors

These are the most effective medications for Zollinger-Ellison syndrome. Proton pump inhibitors are quite powerful and suppress acid production and promote healing. Examples of proton pump inhibitors include Prilosec, Prevacid, Nexium, Aciphex, and Protonix.

Acid blockers

These are also called histamine (H-2) blockers. These medications reduce the amount of hydrochloric acid released into the digestive tract. This helps to relieve ulcer pain and encourage healing. Acid blockers work by keeping histamine from reaching histamine receptors. Histamine receptors signal acid-secreting cells in the stomach to release hydrochloric acid. Examples of acid blockers include Tagamet, Pepcid, Zantac, and Axid.

Acid blockers don't work as well as proton pump inhibitors do, and may not be prescribed by the doctor. For those people who do use acid blockers, they need high, frequent doses for them to be effective.

Prevention for Zollinger-Ellison Syndrome

At this moment, there are no ways to prevent Zollinger-Ellison Syndrome. There is some genetic testing, available for patients who know that there is a family history of serious peptic ulcers or gastrointestinal tumors. These tests cannot prevent Zollinger-Ellison syndrome, but can inform patients more about their health.

What Is the Outlook for People with Zollinger-Ellison Syndrome?

Gastrinomas tend to grow slowly and are not always malignant. The five-year survival rate depends on whether tumors are cancerous and if they've spread. If they have not spread to the liver, the fifteen-year survival rate is approximately 83%. This drops to a ten year survival of about 30% if the tumors have spread to the liver.