RT Journal Article SR Electronic T1 Novel immunohistochemical markers differentiate intrahepatic cholangiocarcinoma from benign bile duct lesions JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP 619 OP 626 DO 10.1136/jclinpath-2015-203418 VO 69 IS 7 A1 Bertram, Stefanie A1 Padden, Juliet A1 Kälsch, Julia A1 Ahrens, Maike A1 Pott, Leona A1 Canbay, Ali A1 Weber, Frank A1 Fingas, Christian A1 Hoffmann, Andreas C A1 Vietor, Antonie A1 Schlaak, Joerg F A1 Eisenacher, Martin A1 Reis, Henning A1 Sitek, Barbara A1 Baba, Hideo A YR 2016 UL http://jcp.bmj.com/content/69/7/619.abstract AB Aims The distinction between intrahepatic cholangiocarcinoma (ICC) and benign bile duct lesions can be challenging. Using our previously identified potential biomarkers for ICC, we examined whether these are useful for the differential diagnosis of ICC, bile duct adenoma and reactive bile duct proliferations in an immunohistochemical approach and identified a diagnostic marker panel including known biomarkers.Methods Subjects included samples from 77 patients with ICC, 33 patients with bile duct adenoma and 47 patients with ductular reactions in liver cirrhosis. Our previously identified biomarkers (stress-induced phosphoprotein 1 (STIP1), SerpinH1, 14-3-3Sigma) were tested immunohistochemically following comparison with candidates from the literature (cluster of differentiation 56, heat shock protein (HSP)27, HSP70, B-cell-lymphoma2, p53, ki67).Results The expression of SerpinH1 and 14-3-3Sigma was significantly higher in ICC than in bile duct adenomas and ductular reactions (p<0.05), whereas STIP1 expression was significantly higher (p<0.05) in ICC than in ductular reactions, but the difference to the bile duct adenoma group was not significant. A panel of the biomarker SerpinH1, 14-3-3Sigma and ki67 (≥2 marker positive) showed a high diagnostic accuracy (sensitivity 87.8%, specificity 95.9%, accuracy 91.8%) in the differential diagnosis of ICC versus non-malignant bile duct lesions.Conclusions This suggests that 14-3-3Sigma and SerpinH1 may be useful in the differential diagnosis of malignant, benign and reactive bile duct lesions in addition to ki67 where a cut-off of >5% might be used for the distinction of malignant and non-malignant lesions.