Successful endoscopic mucosal resection for non-ampullary duodenal signet-ring cell carcinoma

We present a case of non-ampullary duodenal signet-ring cell carcinoma treated by endoscopic mucosal resection. The patient is a 61-year-old male with a history of coronary artery bypass grafting, hypertension, dyslipidemia, and diabetes mellitus complicated by end-stage renal disease requiring peritoneal dialysis who presented for routine endoscopic screening. A 9 mm protruding mass was found in the second part of the duodenum, proximal to the ampulla of Vater. Biopsy of the mass revealed proliferation of signet-ring cells with vacuolated foamy cytoplasm and displaced ovoid nuclei, consistent with signet-ring cell carcinoma. We performed endoscopic mucosal resection and achieved margin-free resection without complications. No recurrence was seen during the 24 months of follow-up. Duodenal signet-ring cell carcinoma is a rare entity most commonly occurring in the ampulla of Vater. This is the first report of successful endoscopic mucosal resection for early non-ampullary duodenal signet-ring cell carcinoma.