Incidental Gastric Adenomyoma during Bariatric Surgery: Diagnostic and Management Challenges - A Case Report

Background: Incidental gastric tumours, including benign gastric adenomyoma (GA) during bariatric surgery, can pose diagnostic and management dilemmas, resulting in misdiagnosis, inappropriate procedures, or even abandoning the procedure. Case Presentation: We report a rare case of an incidental prepyloric GA discovered during a one-anastomosis gastric bypass performed for diabetes management. Preoperative gastroscopy was unremarkable, but intraoperative laparoscopy revealed a mass near the pylorus resembling a gastrointestinal stromal tumour (GIST). An initial histopathological examination was non-confirmatory. However, subsequently, it was confirmed to be a GA. The patient underwent a staged surgical approach, achieving diabetic control during the primary procedure and tumour excision subsequently. This is the first documented case of GA discovered during bariatric surgery. Conclusion: Gastric tumours identified during bariatric procedures necessitate an individualized approach considering the procedure planned, tumour characteristics, and anatomical location, to achieve the best clinical outcomes.