“…20,25,27–29 In a small series of 37 patients with hilar cholangiocarcinoma, Hidaka 28 noted that a greater histologic depth of invasion tended to be associated with a worse long-term outcome. In a separate study, Nagahashi et al 29 reported that long-term outcome after resection of extrahepatic cholangiocarcinoma was associated with depth of tumor invasion.…”