Gastrointestinal Stromal Tumor



The cause is not well understood. Many people with a GIST have a defect in a certain gene. The gene is active when it should not be. This allows cells to grow and divide without order. This may explain why a GIST forms.

Risk Factors

This problem is more common in people who are over 50 years of age. Other things that may raise the risk are:

  • Inherited conditions such as neurofibromatosis type 1
  • A family history of GIST (rare)



Problems may be:

  • Tiredness and weakness
  • Nausea or vomiting
  • Problems swallowing
  • Feeling full after eating a small amount of food
  • Weight loss
  • Swelling or a lump in the belly
  • Belly pain
  • Blood in stool or vomit


The doctor will ask about your symptoms and health history. This may be enough to suspect the diagnosis.

Images may be taken. This can be done with:

  • Abdominal CT scan
  • MRI scan
  • PET scan

A sample of the tumor will be taken to confirm the diagnosis. This can be done with a fine-needle biopsy.

Genetic tests may also be done. This can be done with blood tests.



Treatment will depend on the size of the tumor and whether it has spread. Options are:

  • Monitoring very small tumors for any changes
  • Medicines to shrink the tumor or stop it from growing
  • Surgery to remove some or all of a tumor that has not spread


There are no known methods to prevent this health problem.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.