Abstract:

 Gastrointestinal stromal tumours ( GISTs) are the most common  mesenchymal tumours of the GI tract. They occur most frequently in stomach (60-70%), or small intestine(SI) ( 25-30%). Rare sites include colon, rectum, appendix and esophagus (<10%). On histology their appearance varies from cellular spindle cell tumours to epithelioid to pleomorphic tumours. Traditionally, three criteria have been used to determine malignancy, which include site of origin (SI and rectal tumours  are more aggressive than stomach tumours), tumour size( >5 cm) and mitotic rate.(>5/50 hpf ).GISTs are characterized by gain of function mutation in c kit (CD117) proto oncogene most commonly involving exon 11. GISTs without c kit mutation show mutations in  platelet derived growth factor receptor alpha( PDGFRα).Surgery has been the standard treatment for resectable GISTs, but  metastatic and unresectable GISTs had a poor prognosis. Recent molecular advances have opened new vistas leading to the development of specific molecular targeted therapies which stabilize the disease and reduce the frequency of disease recurrence. This review summarizes our existing knowledge, recent advances regarding histogenesis, pathology, molecular biology, and targeted cancer therapies which has revolutionized the management of these diseases.    

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