Gastrointestinal stromal tumor (GIST) occur from mutation of-

GIST is the most common mesenchymal tumor of the abdomen PATHOGENESIS Approximately 75% to 80% of all GISTs have oncogenic, gain-of-function mutations of the gene encoding the tyrosine kinase c-KIT, which is the receptor for stem cell factor. Another 8% of GISTs have mutations that activate a related tyrosine kinase, platelet-derived growth factor receptor A (PDGFRA); thus activating mutations in tyrosine kinases are found in viually all GISTs. However, either mutation is sufficient for tumorigenesis, and c-KIT and PDGFRA mutations are almost never found in a single tumor. GISTs appear to arise from, or share a common stem cell with, the interstitial cells of Cajal, which express c-KIT, are located in the muscularis propria, and serve as pacemaker cells for gut peristalsis. TEXT BOOK OF ROBBINS BASIC PAYHOLOGY NINTH EDITION PAGE.572 IMAGE REF: