LAUSR

Gastrointestinal stromal tumor (GIST) is a rare neoplasm of the alimentary tract with an incidence of around 1 per 100,000 [1]. The most common location is in the stomach where 60% of these tumors occur [2]. Incidence in the stomach is therefore 6 per 1,000,000. Laparoscopic sleeve gastrectomy (LSG) provides pathological specimens of the majority of the stomach. Therefore, patients undergoing LSG are an advantageous cohort for studying the incidence of GIST. A previous published report from our registry described an incidence of 0.6% for GIST in the stomach in this population, which was 1000 times more common than the accepted incidence in the literature [3]. Since that report we have frequently encountered GIST during LSG, perhaps due to increased awareness. A new search of our registry showed that 1052 patients underwent LSG between 2007 and 2016. Eleven patients had GIST in their resected stomach, an incidence of more than 1%. This incidence is 66% higher even than our previous report. The group of patients with GIST had lower BMI and older age compared to the control group. There were no statistically significant differences in comorbidities. Tumor size ranged between 2 and 28 mm with a mean size of 9 mm. All tumors had low mitotic index. Laparoscopic sleeve gastrectomy was completed in all patients, sometimes with mild deviation from the standard technique. GISTs are found more and more commonly in metabolic surgery across the world. This may be due to an association between these tumors and obesity, or because asymptomatic GISTs are rarely diagnosed in the general population. These tumors are particularly common in older patients and special attention must be given when performing LSG on them. It is important to examine the specimen macroscopically and actively seek these tumors. If thorough macroscopic examination is performed microscopic evaluation may be of little added value in most cases [4]. The malignant potential and risk of recurrence of the vast majority of these resected tumors is extremely low according to accepted nomograms [5]. Although the management of GIST smaller than 2 cm is controversial, it seems these patients do not require special oncological follow up after LSG.