Gastric cancer after bariatric surgery - a diagnostic challenge.

INTRODUCTION: Bariatric surgery is an effective treatment for severe obesity, offering substantial improvements in patients' metabolic profiles. However, increasing attention is being paid to potential long-term complications, including malignancies developing in the excluded portion of the stomach - an area that poses significant diagnostic challenges. CASE REPORT: We report the case of a 68-year-old woman with a history of biliopancreatic diversion, who was diagnosed with advanced diffuse gastric carcinoma 10 years after surgery. The clinical presentation was non-specific, and both laboratory and imaging studies repeatedly yielded false-negative results. A definitive diagnosis was established only during diagnostic laparoscopy - unfortunately, at a stage too advanced for curative treatment. CONCLUSION: This case underscores the risk of late-onset malignancy in the excluded stomach following bariatric surgery and highlights the considerable diagnostic difficulties. Early detection requires a high index of clinical suspicion, access to advanced endoscopic techniques, and close multidisciplinary collaboration. The absence of standardized screening protocols further hampers timely diagnosis.