Fig. 6

Histological findings following hematoxylin and eosin staining. a Hemorrhage under the bile duct epithelium (dotted black arrow) at a site irrelevant to the CIS. Embolic material (dotted yellow arrow) is observed in the ruptured artery (solid black arrow), which is interpreted as the cause of hemorrhage. Hemorrhage site (solid yellow arrow) is accompanied by vascular proliferation that is considered to have existed before the hemorrhage. b Image of the CIS. No ulcer was observed