This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
Gastrointestinal stromal tumors (GIST) are a type of soft tissue tumor that usually begin in specialized nerve cells in the wall of the stomach, intestines, or rectum, known as interstitial cells of Cajal. GIST may be noncancerous (benign) or cancerous (malignant). If cancerous, the tumor may also be called a soft tissue sarcoma. Symptoms depend on the location, size, and aggressiveness of the tumors, but may include vomiting of blood, bloody or tarry bowel movements, or anemia caused by chronic bleeding. Other symptoms may include painful and swollen abdomen, appendicitis-like pain, or complications due to gastrointestinal obstruction or tumor rupture.
GIST may only affect one member of a family (not inherited) or several family members (familial or inherited). The risk of GIST is increased in people who have a certain variations (mutations) in the KIT gene, PDGFRA genes, and possibly a few other genes. Disease-causing variations in these same genes are also involved in the non-inherited form of GIST, but the genetic variation occurs accidentally during a person’s life time (acquired) rather than being passed down from one or both parents. Familial GIST, which usually involves more than one tumor, may follow an autosomal dominant or autosomal recessive inheritance pattern depending on the genetic variation.
Treatment may include surgery to remove the tumors, and/or medication with tyrosine kinase inhibitors (TKI) depending on the extent of disease and tumor sensitivity to TKI. In very rare cases GIST may be part of a genetic syndrome, such as Neurofibromatosis type 1 (NF1) and Carney triad. The prognosis depends on the severity, size, location of the tumor and whether the tumor is cancerous, can be removed by surgery, or if it has spread to other parts of the body (metastasized).
For more information, visit GARD.