RT Journal Article SR Electronic T1 Copper deposition in focal nodular hyperplasia and inflammatory hepatocellular adenoma JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP jclinpath-2017-204820 DO 10.1136/jclinpath-2017-204820 A1 Vishal S Chandan A1 Sejal S Shah A1 Taofic Mounajjed A1 Michael S Torbenson A1 Tsung-Teh Wu YR 2017 UL http://jcp.bmj.com/content/early/2017/11/09/jclinpath-2017-204820.abstract AB Aims To examine copper deposition in focal nodular hyperplasia (FNH) and inflammatory hepatocellular adenoma (IHA) and to determine if it can play a role in their differentiation.Methods 28 FNHs and 19 IHAs from surgical resections showing typical morphological and immunohistochemical features were stained with rhodanine to evaluate for copper deposition. Histological features such as nodularity, fibrous bands, ductular proliferation, steatosis, ballooned hepatocytes and lymphocytic inflammation were also scored.Results Copper deposition was detected in 96% (27/28) of FNHs and 37% (7/19) of IHAs, P<0.001. In all cases, copper was seen within the hepatocytes only around the pseudo-portal tracts or areas of fibrosis. Copper deposition in IHA was significantly associated with presence of lymphocytic inflammation (P=0.04) but not associated with features like nodularity, fibrous bands, ductular proliferation, ballooned hepatocytes and steatosis (P>0.05, for all). In FNH, the presence and degree of copper deposition was not significantly associated with any histological features (P>0.05, for all).Conclusions Copper deposition occurs more frequently in FNH (96%) than IHA (37%), P<0.001. However, the presence of copper alone cannot be used as a feature to differentiate between FNH and IHA.