Signs and Symptoms of Gastrointestinal Stromal Tumors

Most gastrointestinal stromal tumors (GISTs) occur in the stomach or small intestine. These tumors often grow into the empty space inside the gastrointestinal (GI) tract, so they might not cause symptoms right away unless they are in a certain location or reach a certain size.

Small tumors might not cause any symptoms and may be found accidentally when the doctor is looking for some other problem. These small tumors often grow slowly.

Symptoms related to blood loss

GISTs tend to be fragile tumors that can bleed easily. In fact, they are often found because they cause bleeding into the GI tract. Signs and symptoms of this bleeding depend on how fast it occurs and where the tumor is located.

  • Brisk bleeding into the esophagus or stomach can cause the person to throw up blood. When the blood is thrown up it may be partially digested, so it might look like coffee grounds. 
  • Brisk bleeding into the stomach or small intestine can make bowel movements (stools) black and tarry.
  • Brisk bleeding into the large intestine is likely to turn the stool red with visible blood.
  • If the bleeding is slow, it often doesn’t cause the person to throw up blood or have a change in their stool. Over time, though, slow bleeding can lead to a low red blood cell count (anemia), and make a person feel tired and weak.

Bleeding from the GI tract can be very serious. If you have any of these signs or symptoms, see a doctor right away.

Other possible symptoms of GISTs

Other symptoms of GISTs can include:

  • Abdominal (belly) pain
  • A mass or swelling in the abdomen
  • Nausea, vomiting
  • Feeling full after eating only a small amount of food
  • Loss of appetite
  • Weight loss
  • Problems swallowing (for tumors in the esophagus)

Sometimes the tumor grows large enough to block the passage of food through the stomach or intestine. This is called an obstruction, and it can cause severe abdominal pain and vomiting. Because GISTs are often fragile, they can sometimes rupture, which can lead to a hole (perforation) in the wall of the GI tract. This can also result in severe abdominal pain. Emergency surgery might be needed in these situations.

Although many of the possible symptoms of GISTs (like belly pain and nausea) can be caused by things other than cancer, if you have these symptoms, especially if they last for more than a few days, it's important to see a doctor.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master’s-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Casali PG, Dei Tos AP, Gronchi A. Chapter 55: Gastrointestinal Stromal Tumor. In: DeVita VT, Lawrence TS, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg’s Cancer: Principles and Practice of Oncology. 10th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2015.

National Cancer Institute. Physician Data Query (PDQ). Gastrointestinal Stromal Tumors Treatment. 2017. Accessed at www.cancer.gov/types/soft-tissue-sarcoma/hp/gist-treatment-pdq on April 17, 2017.

Last Medical Review: May 17, 2017 Last Revised: May 17, 2017

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