Gastrointestinal Stromal Tumors (GIST) are sarcomas that may develop in specialized cells called the interstitial cells of Cajal (ICCs), which line the wall of the entire digestive system, including the stomach, esophagus, intestines, anus and rectum. ICCs are part of the autonomic nervous system, which sends signals to the muscles of the digestive system, telling it to contract during peristalsis, the process by which food moves through the system and is turned into nutrients the body can use.
Symptoms usually depend on tumor size and location, but many patients have no symptoms. In these cases, the tumors are often discovered incidentally during surgery for other conditions.
In the early stages of GIST, there are few symptoms. However, as the tumor develops, it may cause:
- Abdominal pain
- Nausea or vomiting
- Feeling full after a small meal
- Loss of appetite
- Weight loss
- Problems swallowing
- Bleeding that turns bowel movements black and tarry, or causes vomiting of blood
- Weakness or fatigue from anemia, related to bleeding
- Intestinal obstruction if the tumor grows large enough to block the GI system