Intrabiliary Growth of Liver Metastases

Intrabiliary growth by metastatic colorectal carcinoma (CRC) is an unusual finding that can clinically mimic cholangiocarcinoma. We evaluated prevalence of intrabiliary growth by retrospective review of 1596 diagnostic reports and by prospective evaluation of 223 hepatectomies. Positive cases were scored for extent of intrabiliary growth (major vs. minor duct involvement), architectural pattern (colonization of biliary epithelium and/or intrabiliary tumor plugs), and secondary sclerosing cholangitis in non-neoplastic parenchyma. By retrospective review, we identified intrabiliary growth in 41 (3.6%) of 1144 metastatic CRCs but only 3 (0.7%) of 452 noncolorectal tumors (P