Print OverviewA gastrointestinal stromal tumor, also called a GIST, is a type of cancer that begins in the digestive system. GISTs happen most often in the stomach and small intestine. A GIST is a growth of cells that's thought to form from nerve cells in the walls of the digestive organs. The nerve cells play a part in the process that moves food through the body. Small GISTs may cause no symptoms. And GISTs may grow so slowly that they don't cause problems at first. As a GIST grows, it can cause symptoms that may include belly pain and nausea. GISTs can happen in people at any age, but they are most common in adults and very rare in children. The cause of most GISTs isn't known. Products & ServicesA Book: Mayo Clinic Family Health BookNewsletter: Mayo Clinic Health Letter — Digital EditionShow more products from Mayo Clinic SymptomsGastrointestinal stromal tumor symptoms include: A growth in the belly area. Belly pain. Fatigue. Nausea and vomiting. Not feeling hungry when you would expect to. Feeling full if you eat only a small amount of food. Dark-colored stools caused by bleeding in the digestive system. When to see a doctorMake an appointment with a doctor or other healthcare professional if you have any symptoms that worry you. Request an appointment CausesThe cause of a gastrointestinal stromal tumor often isn't known. This cancer, which also is called a GIST, happens in the digestive system. It most often affects the stomach and small intestine. GISTs are thought to begin in nerve cells in the walls of the digestive organs. These nerve cells play a part in the process that moves food through the body. A GIST starts when nerve cells in the digestive system develop changes in their DNA. A cell's DNA holds the instructions that tell the cell what to do. In healthy cells, the DNA gives instructions to grow and multiply at a set rate. The instructions tell the cells to die at a set time. In cancer cells, the DNA changes give different instructions. The changes tell the cancer cells to grow and multiply quickly. Cancer cells can keep living when healthy cells would die. This causes too many cells. The cancer cells might form a mass called a tumor. The tumor can grow to invade and destroy healthy body tissue. In time, cancer cells can break away and spread. When cancer spreads, it's called metastatic cancer. Risk factorsRisk factors for gastrointestinal stromal tumor, also called GIST, include: Family history. People with a family history of GISTs may be at increased risk of this cancer. Hereditary syndromes. People with some conditions that run in families may be more likely to have GISTs. Examples include neurofibromatosis type 1 and Carney-Stratakis syndrome. Adult age. A GIST can happen at any age. This cancer happens most often in adults. It's rare in children. By Mayo Clinic Staff Request an appointment Diagnosis & treatment Feb. 25, 2025 Print Living with gastrointestinal stromal tumor (gist)? Connect with others like you for support and answers to your questions in the Sarcoma support group on Mayo Clinic Connect, a patient community. Sarcoma Discussions Undifferentiated Pleomorphic Sarcoma: Anyone else want to share? 113 Replies Sun, Feb 23, 2025 chevron-right Myxofibrosarcoma: What treatments did you have? 111 Replies Sun, Feb 23, 2025 chevron-right Anyone have experience with gastrointestinal stromal tumor (GIST)? 79 Replies Sun, Feb 23, 2025 chevron-right See more discussions Show references Feldman M, et al., eds. Gastrointestinal stromal tumors. In: Sleisenger and Fordtran's Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, Management. 11th ed. Elsevier; 2021. https://www.clinicalkey.com. Accessed Dec. 8, 2021. Gastrointestinal stromal tumors (GISTs). National Comprehensive Cancer Network. https://www.nccn.org/guidelines/guidelines-detail?category=1&id=1507. Accessed Nov. 8, 2024. Goldblum JR, et al. Gastrointestinal stromal tumor (GIST) and extragastrointestinal GIST. In: Enzinger and Weiss's Soft Tissue Tumors. 7th ed. Elsevier; 2020. https://www.clinicalkey.com. Accessed Dec. 8, 2021. Hu S, et al. Gastrointestinal stromal tumors (GISTs) arising in uncommon locations: Clinicopathologic features and risk assessment of esophageal, colonic, and appendiceal GISTs. Modern Pathology. 2022; doi:10.1038/s41379-021-00949-w. Related Associated Procedures Palliative care Products & Services A Book: Mayo Clinic Family Health Book Newsletter: Mayo Clinic Health Letter — Digital Edition Show more products and services from Mayo Clinic Gastrointestinal stromal tumor (GIST)Symptoms&causesDiagnosis&treatmentDoctors&departments Advertisement Mayo Clinic does not endorse companies or products. 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