Pathological aspects of so called "hilar cholangiocarcinoma"

Figure 5 Examples of the broad morphological spectrum of hilar bile duct carcinoma. A: Well differentiated biliary type adenocarcinoma (HE stain, ×40); B: A case with well defined tumor glands interspersed with poorly differentiated small tumor groups an single tumor cells (besides, biliary intraepithelial neoplasia 3 can be observed on the duct surface) (HE stain, ×100); C: A case with poorly differentiated cell component with resembling signet ring cells (HE stain, ×200); D: Perineural invasion by well differentiated glands (HE stain, ×40).