Carcinoma in situ arising in a tubulovillous adenoma of the distal common bile duct: A case report

Figure 1 Ultrasound examination reveals a 2 cm sized non-shadowing mass and a dilated common bile duct (arrow).

Figure 2 Computed tomography shows a diffuse dilatation of the common bile duct with an intraluminal mass in the distal common bile duct.

Figure 3 Endoscopic retrograde cholangiopancreatography shows a 2 cm round lobulated filling defect in the distal common bile duct (arrows).

Figure 4 A photograph of the pylorus-preserving pancreaticoduodenectomy specimen shows a polypoid mass in the distal common bile duct, 2 cm x 1. 5 cm x 1.5 cm size (arrows).

Figure 5 Microscopic features of the tubulovillous adenoma. Hematoxylineosin stain. A: The elongated and pseoudostratification of nuclei are stained (× 40); B: Higher magnification on this slide demonstrates carcinoma in situ (asterisk; × 100).