Management of transpyloric invagination of a gastrointestinal stromal tumor (GIST)
Epublication WebSurg.com, Feb 2012;12(02). URL: http://websurg.com/doi/vd01en3568
Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. GISTs are most commonly found in the stomach (40-70%), but can occur in all other parts of the GI tract, with 20 to 40% of GISTs arising in the small intestine and 5 to 15% from the colon and rectum. They typically grow endophytically, parallel to the bowel lumen, commonly with overlying mucosal necrosis and ulceration. They also vary in size, from a few millimeters to 40cm in diameter. Many GISTs are well defined by a thin pseudo-capsule. Over 95% of patients present with a solitary primary tumor, and in 10 to 40% of these cases, the tumor directly invades neighboring organs. Gastric GISTs are usually presented with GI bleeding and abdominal pain. However, most patients are symptom-free and the lesions are discovered incidentally during an upper endoscopy performed for other reasons (chronic abdominal pain and intermittent gastric obstruction in this patient). Surgery remains the mainstay of curative treatment. Surgical resection of localized gastric GISTs is the preferred treatment modality, as resection of the tumor renders the only chance for cure at this time. Historically, a 1 to 2cm margin was thought to be necessary for an adequate resection. However, more recently, DeMatteo et al. demonstrated that tumor size and not negative microscopic surgical margins determine survival. It is therefore accepted that the surgical goal should be a complete resection with gross negative margins only. Given this, wedge resection has been advocated by many investigators for the majority of gastric GISTs.