GIST is the most common mesenchymal tumor of the gastrointestinal tract. It has the phenotypic features of Cajal mesenchymal cells in differentiation, is usually DOG-1 and CD117 positive on immunohistochemistry, and consists of spindle cells, epithelioid cells, and pleomorphic cells (occasionally) arranged in bundles or diffusely distributed on histology. Most are driven by mutated c-kit or PDGFRA (platelet-derived growth factor receptor) genes. c-kit and PDGFRA both belong to a family of type III receptor-coupled tyrosine kinases. In 1998, a major breakthrough in the molecular pathology of GIST suggested that the majority (75%-85%) of GISTs were associated with functionally acquired mutations in the c-kit gene and that expression of the c-kit gene protein product CD117 was a characteristic molecular pathology of GIST. in 2003, Heinrish et al. in GISTs without c-kit gene mutations, an additional mutations in the PDGFRA gene. In recent years, BRAF gene mutations have been found in a minority of cases (about 4%-13%) without c-kit and PDGFRA gene mutations. GIST covers the majority of gastrointestinal mesenchymal tumors that were previously diagnosed as smooth muscle-derived (smooth muscle tumor, smooth muscle sarcoma, smooth muscleoblastoma) or neurogenic (gastrointestinal autonomic neoplasm) and exhibit a continuous spectrum from benign to apparently malignant in terms of biological behavior.