A Rare Submucosal Lesion of the Duodenum.

We reported a rare case of submucosal lesion of the duodenum in a 68-year-old male. It was accidentally found during an abdominal MRI examination. Further evaluation with gastroduodenoscopy revealed a 2 cm mass in the duodenal bulb. EUS identified a hypoechoic mass with a hyperechoic region inside, originating from the muscular layer, with poorly defined borders relative to the surrounding tissues. Following resection via endoscopic full-thickness resection (EFTR), pathological examination confirmed adenocarcinoma infiltrating the muscular layer, with chronic schistosomiasis.