Gastrointestinal stromal tumors (GISTs) are the most common (80%) mesenchymal tumors of the alimentary canal, accounting for less than 1% of all gastrointestinal tumors and about 5% all sarcomas with relative incidence in Egypt about 2.5% of all gastrointestinal tumors and 0.3% of all malignancies. They arise from interstitial cells of Cajal (ICC) or their stem cell precursors which are normally are part of the autonomic nervous system of the intestine and serves as a pacemaker function in controlling motility. Molecular pathological studies have shown that most GISTs express KIT, a type III receptor tyrosine kinase, and have gain of function mutation of the KIT gene or the platelet-derived growth factor receptor alpha (PDGFRA) gene.