Incidental Gastrointestinal Stromal Tumors (GISTs) and Bariatric Surgery: A Review

The number of bariatric procedures has increased notably, with incidental findings such as gastrointestinal stromal tumors (GISTs) being observed in 2%. The number of studies dealing with incidental findings during bariatric surgery (BS), especially GISTs, is scarce. This review aims to summarize the evidence about GIST diagnosis during BS, and to establish recommendations for the management and follow-up of these patients. A systematic literature search from January 2000 to March 2020 was performed. Retrospective cohort studies, case series, case reports, reviews, and conference abstracts were considered eligible. The present systematic review focused on a descriptive analysis of the data included in the articles selected. The calculated incidence was 0.65%. A change in operative plan was observed in 5% of the cases. In 98% of the cases, GISTs were gastric, with a mean size of 10.3 mm. The mitotic index was < 5 in 99%. Accordingly, all patients were classified as having a very low or low risk of recurrence. R0 resection was achieved in 100% of cases. The incidence of GISTs in patients with MO submitted to BS is considerably higher than in the general population. The diagnosis is related to the depth of preoperative work, the exhaustiveness of the intraoperative examination, and the meticulousness of the histopathological analysis. Although GISTs have a low risk of recurrence and it was previously unnecessary to modify the surgical technique, we recommend that bariatric surgeons are aware of the diagnosis and management of incidental GISTs.

Keywords: Bariatric surgery; GIST; Gastrointestinal stromal tumors; Morbid obesity.