Gastrointestinal stromal cell tumor (GIST)

GIST is caused by a change in the genetic makeup of a cell. That cell is located in the muscle layer of the gastrointestinal tract. This change causes the cell to divide quickly and uncontrollably. This creates a tumor: GIST. Yeasts can occur throughout the gastrointestinal tract. They usually occur in the stomach.

• stomach: 50-60%
• Small intestine: 20-30%
• rectum: 10%
• colon: 5%
• Esophagus: 5%

Every year, about 1.5 out of every 100,000 people get GIST. In the Netherlands, that is about 250 people a year.

In most people, GIST develops without a clear cause. There are no known risk factors. In a small group of patients, about 5%, GIST is caused by an underlying genetic disorder.

A smaller tumor (smaller than 2 cm) often does not cause any symptoms. This is usually found by chance during an examination for another reason. Larger tumors can cause specific symptoms. The symptoms are usually due to the size of the tumor or to bleeding.

Complaints due to the size of the tumor may include:

• bellyache
• nausea
• problems with bowel movements
• difficulty eating
• a swelling in the abdomen

If there is bleeding, you may see blood in your stool or vomit. Sometimes you notice it in symptoms of anemia, such as fatigue.