Incidental Finding of GIST in Morbidly Obese Patients Undergoing Laparoscopic Sleeve Gastrectomy

A Mooney, MD, S McNatt, MD, M Powell, MD, A Fernandez. Wake Forest University

Background: Gastrointestinal stromal tumor (GIST) is reported as a rare neoplasm in the general population with an incidence of 1 per 100,000.  Laparoscopic sleeve gastrectomy (LSG) provides specimens of the majority of the stomach for review.  Recent data suggest this incidence may be higher in the morbidly obese population.  The aim of this study was to review pathology from our LSG specimens and identify the incidence of GIST and other histopathologies at our institution.

Methods: A retrospective review of LSG cases at our institution was performed between December 2013 to July 2015.  Data obtained included age, gender, BMI, h. pylori serology, co-morbid conditions (hypertension, diabetes, reflux disease), and histopathology report. 

Results: Pathology reports of 265 LSG patients revealed incidental GIST in 5 patients (2%).  The tumor sizes ranged from 0.3 to 2.5 cm, all with negative margins.  The tumors were located at the greater and lesser curve, fundus, and GE junction.  H. pylori was identified in 35 patients (13%) and chronic gastritis in 92 patients (35%).  Neither h. pylori nor gastritis were associated with GIST pathology.

Conclusions:  Although GIST is reportedly rare in the general population, the incidence in our cohort is much higher.  This could be due to underdiagnosed lesions in the asymptomatic person or a true association with obesity.  More research should investigate this association.  The surgeon must recognize the increased incidence of GIST in the morbidly obese population and pay special attention to abnormal tissue encountered.   LSG is a safe operation for negative margin resection of incidentally found GIST.