Gastrointestinal stromal tumors of the stomach.

Gastrointestinal stromal tumors (GISTs) are relatively rare mesenchymal tumors located within the submucosa of the GI tract. The defining characteristic of GISTs is the presence of the cell-surface antigen CD117 receptor tyrosine kinase, identified by immunohistochemistry. Currently the only cure for GIST is complete surgical resection. Imatinib has revolutionized the treatment of GISTs and has been used as adjuvant treatment after resection, and as treatment for locally advanced, recurrent, and metastatic GIST. Imatinib resistance has become a significant concern in the treatment of GISTs and other tyrosine kinase inhibitors that target different pathways are currently being studied.