BS SO17 - Large Bowel Occlusion as a Manifestation of Gastric Adenocarcinoma in a Patient with Previous Gastric Bypass

Abstract Background Gastric bypass surgery has become one of the hallmarks of the treatment of obesity and metabolic syndrome. Over the last decade, an increasing number of gastric cancer cases have been reported following gastric bypass, particularly in the excluded stomach. The anatomical changes and the difficult access to the excluded stomach via endoscopy hinder the diagnosis and treatment of this cancer. Method Literature review and clinical case analysis through clinical records and exam results. Results A 59-year-old male with a history of gastric bypass 15 years prior was admitted to the emergency department with bowel occlusion. A CT scan revealed colonic obstruction due to invasion by a neoplastic/inflammatory process. Consequently, a right hemicolectomy was performed. Histopathological analysis revealed infiltration of the colonic wall by poorly cohesive gastric carcinoma cells. A follow-up CT scan confirmed a lesion in the excluded stomach. A LAMS (lumen-apposing metal stent) was placed to repermeabilize the excluded stomach, and biopsies confirmed gastric mixed adenocarcinoma. A gastroduodenal stent was placed for antropyloric stenosis. A multidisciplinary team opted for palliative chemotherapy. Conclusion The association between bariatric surgery and gastric cancer remains controversial. As described in previous studies, this clinical case demonstrates that gastric adenocarcinoma in patients who underwent gastric bypass often presents as an aggressive and advanced-stage disease. Given the mortality associated with gastric cancer and the increasing number of bariatric surgeries, this case report highlights the important need to develop patient selection protocols for gastric bypass and respective appropriate follow-up.