Extragastrointestinal stromal tumour of the transverse mesocolon mimicking giant ovarian cystic neoplasm.

Gastrointestinal stromal tumours (GISTs) are mesenchymal tumours which are most commonly found along the gastrointestinal tract. They are more rarely found in an extragastrointestinal location and typically present late due to only vague symptoms from mass effect. There are very few case reports of GIST arising within the transverse mesocolon. We report a case of a large cystic transverse mesocolic GIST which preoperative imaging concluded was likely of ovarian origin. This resulted in an abrupt change in the surgical management intraoperatively, but fortunately, an R0 resection was still achieved. This serves as an important lesson to keep the differential diagnosis broad when dealing with large cystic abdominal masses. The tumour was found to be KIT wild type, with a platelet-derived growth factor receptor alpha D842V mutation identified, conferring intrinsic resistance to imatinib.

Bariatric surgery and the neurohormonal switch: Early insulin resistance recordings after laparoscopic sleeve gastrectomy.

Laparoscopic sleeve gastrectomy (LSG) is a bariatric operation with a safe risk profile. It has been proven to successfully reduce weight, decrease insulin resistance (IR), and ameliorate diabetes mellitus. The aim of this study was to determine if there is an early improvement in IR after LSG and its association with weight loss. This was a prospective observational study of 32 patients who underwent LSG at a single center over a 3-year period. Serum insulin and fasting glucose levels were recorded preoperatively, on day 1 postoperatively, and 3 weeks after LSG. IR levels were calculated using the Homeostasis Model Assessment 2 Version 2.23. IR levels were compared along with the overall weight loss, via body mass index. ß-cell function was the secondary outcome. IR significantly improved the day after surgery with a statistically significant mean difference of 0.89 units (P = .043) and significantly more so 3 weeks postoperatively, with a mean difference of 4.32 units (P < .0005). ß-cell function reduced 3 weeks postoperatively, with a mean difference of 23.95 %ß (P = .025), while body mass index significantly reduced, with a mean difference of 4.32 kg/m2 (P < .0005). Early improvement of IR was observed on postoperative day 1 after LSG before any weight loss. This raises the possibility of an undetermined, underlying neurohormonal switch that improves IR. Further investigation is needed to determine this mechanism, as it may lead to an improvement in the medical management of diabetes mellitus.