The Incidence of Gastrointestinal Stromal Tumors in Obese Patients-A Large Single Center Experience.

Background and Objectives: Gastrointestinal stromal tumors (GISTs) are rare mesenchymal neoplasms located mainly in the fundus (60-70%). The incidence of GIST is approximately 10 per million population per year in Europe, with a peak incidence at the age of 63. Recent studies suggest that morbidly obese patients have a higher incidence of GIST than the general population. The aim of this study was to analyze the incidence of GIST in patients undergoing laparoscopic sleeve gastrectomy (LSG) in our department. Materials and Methods: this paper present the retrospective study of prospectively collected data of 1564 patients who underwent LSG in a single large bariatric center from October 2013 to September 2021. After surgery, each sample of the resected stomach was sent for histopathological examination. For the analysis, we included patients diagnosed with GIST intraoperatively or postoperatively. Results: GISTs were found in five patients (0.31%). There were three men and two women. The mean age was 50.2 (range 32-63 ± 11.8) and the mean preoperative body mass index was 43.3 kg/m2 (40-49.4 ± 3.2). In four cases, GISTs were found in the fundus (80%), and in one in the pylorus (20%). None of the tumors were larger than 7 mm in diameter and all were diagnosed as a very low-risk category. No adjuvant treatment was required. All patients achieved good or satisfactory bariatric and metabolic results. Conclusions: The incidence of GIST in our study was estimated at 0.31%. All patients had a very low-risk GIST and no recurrence until follow-up. Recent literature suggests that the risk of GIST is higher in the obese population, and therefore surgeons should be aware of the risk of incidental GIST during LSG.