Primary duodenal carcinoma is rare. Duodenal mucinous adenocarcinoma (DMA) is even rarer, and its associated manifestations and typical endoscopic or imaging findings are not well characterized. Herein, we report a case of primary DMA in an asymptomatic 58-year-old man who visited our hospital for a regular health screening. Upper endoscopy revealed an approximately 4-cm lesion in the second portion of the duodenum, but the mass was not visualized on computed tomography. Biopsies revealed a tubular adenoma that was subsequently resected. Frozen biopsies demonstrated DMA with a background of low-grade tubular adenoma for which we performed Roux-en-Y duodenojejunostomy and jejunojejunostomy. To our knowledge, this is the first report of a patient with DMA in Korea.
Keywords: Adenocarcinoma; Adenoma; Duodenal neoplasms; Mucinous.