The Zollinger-Ellison syndrome (ZES) is a set of symptoms that are caused by cancerous tumors called gastrinomas.

What is going on in the body?

In Zollinger-Ellison syndrome, tumors called gastrinomas produce large amounts of gastrin. This is a hormone that increases the amount of stomach acid. When a large amount of this substance is produced, too much stomach acid is made. This causes sores in the lining of the digestive tract, called peptic ulcers, to form in the stomach and small intestine.

The primary tumors are usually located in the pancreas or small intestine. Occasionally they are found in nearby lymph nodes. Very rarely, they can be located in more distant parts of the body such as the ovaries. The tumors may spread to other parts of the body such as the liver, spleen, lymph nodes, bone, skin and lining of the abdominal cavity.

What are the causes and risks of the condition?

Zollinger-Ellison syndrome is caused by a form of cancer known as a gastrinoma. The extra stomach acid produced by the tumor and the spread of the tumor cause the symptoms of ZES. However, the cause of the gastrinomas is not known. Many people with ZES have an inherited condition that results in an increased risk of this tumor.