Gastric cancer arising in the bypassed stomach after Roux-en-Y gastric bypass: a case report.

INTRODUCTION: Gastric cancer arising in the bypassed stomach after Roux-en-Y gastric bypass (RYGB) is rare but clinically important because delayed diagnosis contributes to advanced-stage presentation, particularly in regions with a high incidence of gastric cancer. CASE: A 70-year-old woman with a prior RYGB was referred after the incidental detection of elevated CA19-9. Computed tomography revealed segmental wall thickening of the antrum in the bypassed stomach, along with suspicious peri-gastric lymph nodes. Standard endoscopy could not access the excluded stomach, and a multidisciplinary discussion determined that tissue acquisition was difficult. Fluorodeoxyglucose positron emission tomography demonstrated intense uptake in the antrum with probable nodal involvement. Given the high radiologic suspicion and the inability to obtain preoperative histology, robotic gastrectomy of the bypassed stomach with D2 lymph node dissection was performed while preserving the gastric pouch. DISCUSSION: In patients who underwent RYGB, malignancy in the bypassed stomach can be difficult to diagnose, as conventional endoscopy cannot access the bypassed stomach. Alternative approaches, such as double-balloon endoscopy or laparoscopic trans-gastric endoscopy, have been reported in the literature, but these techniques are not widely available. In such situations, a multidisciplinary, consensus-driven decision in diagnosis and treatment is important. The published literature consistently reports advanced disease at presentation in these patients. Intraoperatively, adhesions along the staple line between the pouch and the bypassed stomach can pose a technical challenge for the surgeon. CONCLUSION: Gastric cancer in the bypassed stomach after RYGB poses major diagnostic challenges and is frequently at an advanced stage at detection. In high-incidence regions, the choice of bariatric procedure requires individualized consideration, and further research is needed to guide evidence-based procedure selection.