Fig. 1

Enhanced abdominal CT and GI endoscopic findings. Enhanced CT showed stenosis in the third portion of the duodenum in the (A) (red arrow) axial view and (B) (red arrow) coronal view. Enhanced CT also revealed dilatation of the main pancreatic duct (B) (red arrowhead) and atrophy of the pancreatic head. EUS revealed a hypoechoic area at the deep lesion of pancreatic head, approximately 20 mm (C). GI endoscopy revealed one-third circumferential mucosal irregularity from the anal side of the main duodenal papilla to the inferior duodenal angulus, which bled easily (D) (red arrow). A biopsy was performed from the same site. Severe stenosis was observed from the inferior duodenal angulus to the third portion, and the scope could not pass through (E) (red arrow)