Fig. 1

A 58-year-old male was misdiagnosed as having a common bile duct stone by MRI, which was pathologically-confirmed as choledochal adenocarcinoma; (a) MRCP image displays the narrowing (arrow) of the distal CBD suddenly and the expansion of the biliary tract; (b) Axial T1-weighted images and (c) T1-weighted DCE-MRI show high signal nodules in the CBD, and the possibility of stones was considered (arrow), yet no enhancement is seen in the structure of bile duct wall; (d) CUS shows dilated CBD; (e, f) CEUS shows a cauliflower-like mass with uneven enhancement (arrow), which should be considered for common bile duct carcinomas; (g) Histopathological examination reveals that some malignant glands infiltrated into the bile duct wall. CBD: common bile duct; PA: pancreas