Zollinger-Ellison Syndrome

What Is Zollinger-Ellison Syndrome? What Causes Zollinger-Ellison Syndrome?

Zollinger-Ellison syndrome, also known as Strom-Zollinger-Ellison syndrome is a disorder usually caused by a gastrinoma - a tumor - which occurs mainly in the pancreas. The tumor secretes gastrin, a hormone, resulting in excess production of hydrochloric acid in the stomach, which leads to severe recurrent ulcers of the esophagus, stomach, and duodenum and jejunum (upper portions of the small intestine).

Gastrinomas that result in Zollinger-Ellison syndrome may also occur in the duodenum, spleen, lymph nodes and stomach.

Zollinger-Ellison syndrome is a rare disorder. In the USA under 1% of duodenal ulcers result from Zollinger-Ellison syndrome. The disorder more commonly affects people in their 50s, but may occur at any age.

According to Medilexicon's medical dictionary:

Zollinger-Ellison syndrome is "peptic ulceration with gastric hypersecretion and gastrinoma of the pancreas or duodenum, sometimes associated with familial multiple endocrine adenomatosis type 1."


Zollinger-Ellison syndrome is named after two surgeons at the Ohio State University, Robert M. Zollinger (1903-1992) and Edwin H. Ellison (1918-1970).

The stomach, duodenum and pancreas are digestive organs. The stomach secretes gastric acid, as well as other digestive juices that break down food.

When the food is partially digested it moves into the duodenum (the first part of the small intestine), where it is broken down further. The small intestine is the tube-shaped organ between the stomach and the large intestine.

Digestive juices are produced in the pancreas, a large gland - these juices flow into the duodenum. The pancreas also produces hormones which are released into the bloodstream.

What are the signs and symptoms of Zollinger-Ellison syndrome?

A symptom is something the patient senses and describes, while a sign is something other people, such as the doctor notice. For example, drowsiness may be a symptom while dilated pupils may be a sign.

The signs and symptoms of Zollinger-Ellison syndrome include:
  • Discomfort in the upper abdomen
  • Burning and aching sensation in the upper abdomen
  • Diarrhea
  • Bleeding in the digestive tract
  • General weakness
  • Heartburn (gastroesophageal reflux) - gastric acid and food from the stomach backs up into the esophagus. Symptoms may sometimes be severe.
  • Melaena - refers to the black, "tarry" feces, resulting from bleeding in the digestive tract
  • Nausea
  • Unintentional weight loss
  • Vomiting
The signs and symptoms are similar to those of a peptic ulcer.

What are the causes of Zollinger-Ellison syndrome?

Experts are not sure what the exact cause of Zollinger-Ellison syndrome is. We do know that it begins when a gastrinoma (tumor) or gastrinomas form in the pancreas or duodenum. These tumors release gastrin, a hormone.
In normal circumstances, when there is no gastrinoma, the stomach cells produce and control gastrin so that only the right amount is released. The gastrin travels in the bloodstream and signals other stomach cells to release gastric acid to help break down food.

Gastrinomas release excessive quantities of gastrin, resulting in too much gastric acid in the stomach and duodenum, which eventually causes peptic ulcers to form in the lining of the duodenum.

As well as causing excess acid production, the gastrinomas may be malignant (cancerous). The cancer can spread to other parts of the body, most commonly to nearby lymph nodes or the liver.

Experts are not sure what causes the majority of gastrinomas - which appear randomly. In about one quarter of cases, the gastrinomas are caused by multiple endocrine neoplasia type 1 (MEN 1), an inherited genetic disorder. The majority of patients with MEN 1 have multiple tumors in the endocrine system, as well as tumors in the pancreas.

Diagnosing Zollinger-Ellison syndrome

The doctor, often a GP (general practitioner, primary care physician) will interview the patient and ask about symptoms, review their medical history, and possibly order the following diagnostic tests:

Blood tests - to test for raised blood levels of gastrin, which may indicate that there are tumors in the pancreas (or duodenum). The doctor will ask the patient not to eat for a specified length of time before a blood sample is taken. Acid-reducing medications will also have to be stopped for a specified period before the blood test. In most cases the blood test will need to be repeated at least three times, as gastrin levels may fluctuate.

Stomach acidity level - patients which chronic stomach inflammation, as well as those who had recently undergone stomach surgery may have elevated blood gastrin levels even if the stomach does not produce much acid. It is important for the doctor to find out which condition is causing high gastrin levels, and the acidity of the stomach may be tested. If stomach acidity levels are not high, then it is highly unlikely the patient has Zollinger-Ellison syndrome. If the stomach makes acid a secretin stimulation test may be done. The doctor measures gastrin levels, and then injects the hormone secretin, followed by another measurement of gastrin levels. If gastrin levels rise even further, this is indicative of Zollinger-Ellison.

Upper gastrointestinal endoscopy, also known as Upper Endoscopy, upper GI endoscopy, EGD (esophagogastroduodenoscopy) - looking into the esophagus, stomach, and duodenum with an endoscope. An endoscope is a lighted optical instrument with a video camera, used to look deep inside the body and examine internal organs. The doctor inserts the endoscope down the patient's throat and into the stomach and duodenum to look for ulcers. During this procedure a biopsy (tissue sample) may also be taken from the duodenum. The sample will be checked for gastrin-producing tumors. The patient will need to fast for a specified period before this procedure.

Imaging scans - such as a nuclear scan, MRI (magnetic resonance imaging) scan, CT (computerized tomography) scan or ultrasound scan may be used to locate the tumors.

Endoscopic ultrasound - an ultrasound device is inserted inside the patient using an endoscope, so that the doctor can observe his/her stomach and duodenum. An internal ultrasound, such as this one, make it easier to pinpoint tumors and take tissue samples. Fasting is required for a specified period before this procedure.

Angiography - sometimes used to find tumors in the pancreas. A catheter is guided through the bloodstream to blood vessels located in the pancreas. Contrast (dye) material is then injected into the blood vessel through the catheter. The dye shows up on X-ray images, highlighting blood vessels, which tend to be denser inside tumors.

What are the treatment options for Zollinger-Ellison syndrome?

Treatment for Zollinger-Ellison syndrome focuses on the tumors and ulcers. Doctors will usually treat the tumors first.

Tumors - these are usually tricky to remove because they are generally small and hard to find. A single tumor might be surgically removed. However, if there are several tumors, or they have spread over the liver, surgery may not be possible. Sometimes, even if several tumors are present, a single large one may still be surgically removed.

Other treatment options to halt tumor growth may include:
  • A liver transplant
  • Chemotherapy - this may slow down the tumor's rate of growth
  • Debulking - removing as much of the liver as possible.
  • Embolization - cutting of the blood supply to the tumor
  • Injecting drugs directly into the tumor
  • Radiofrequency ablation - using heat to destroy cancer cells
Before modern medications which can control acid production and ulcers were available more radical surgery was more common, including severing the nerves that promote acid secretion, or even surgically removing the whole stomach.

Excess acid treatment - proton pump inhibitors, a type of drug used to control excess acid production, are the first line of treatment. Proton pump inhibitors reduce acid by blocking the action of tiny pumos within acid-secreting cells. Examples include magnesium (Nexium), omeprazole (Prilosec), lansoprazole (Prevacid), pantaprazole (Protonix), rabeprazole (Aciphex), and esomeprazole.

Proton pump inhibitors are much better than histamine (H-2) blockers in treating Zollinger-Ellison syndrome ulcers.

If stomach acid levels drop, the peptic ulcers have a better chance to heal, resulting in less Zillinger-Ellison syndrome symptoms.

Surgery for peptic ulcers - the doctor may suggest:
  • Surgery to close up the perforation in the wall of the stomach or duodenum that was caused by an ulcer
  • Surgery to remove blockage caused by an ulcer
  • Surgery to stop bleeding

 

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