What is a Gastrointestinal Stromal Tumor (GIST)?

Gastrointestinal stromal tumors or GISTs are a form of connective tissue tumor in which abnormal cells form in the tissues of the gastrointestinal tract. The gastrointestinal (GI) tract is part of the body's digestive system. It helps digest food and takes in nutrients from food so they can be used by the body. The GI tract is made up of the stomach, small intestine and large intestine (colon). GISTs may form in the esophagus, stomach, small intestine, colon, rectum, liver, gallbladder, or lining of the gut, but most form in the stomach or small intestine. Some scientists believe that GISTs develop from cells called interstitial cells of Cajal (ICC), which act as pacemakers, controlling the muscles of the GI tract and indirectly helping you digest food. All GISTs have the potential to be malignant.