Published online Jun 8, 2015. doi: 10.4254/wjh.v7.i10.1403
Peer-review started: October 28, 2014
First decision: December 17, 2014
Revised: January 1, 2015
Accepted: March 4, 2015
Article in press: March 5, 2015
Published online: June 8, 2015
Processing time: 218 Days and 6.2 Hours
Immunohistochemistry often plays an important role in the evaluation of liver tumors. Recent advances have established a classification system for hepatocellular adenomas (HCAs) based on morphology, molecular alterations, and immunohistochemistry. Specifically, loss of liver fatty acid binding protein is seen in HNF1α-inactivated HCA, staining with serum amyloid A is seen in inflammatory HCA, and diffuse staining with glutamine synthetase (GS) is seen in β-catenin activated HCA. A panel of immunohistochemical stains including glypican-3 (GPC-3), heat shock protein 70, and GS are useful in distinguishing HCC from non-malignant dysplastic nodules. Immunohistochemistry is also useful to determine whether a liver tumor is of primary hepatocellular or metastatic origin. Recently described markers useful for this purpose include arginase-1, GPC-3, and bile salt export pump. These newer markers may offer superior utility when compared to traditional markers of hepatocellular differentiation such as alpha-fetoprotein, hepatocyte paraffin-1, polyclonal carcinoembryonic antigen, and CD10. This paper will review recent advances in the immunohistochemical evaluation of liver tumors.
Core tip: Immunohistochemical stains may be an important complement to morphology in the characterization of liver tumors. Immunohistochemical stains can now be used to subtype hepatocellular adenomas. A panel of immunohistochemical stains can help distinguish hepatocellular carcinoma from dysplastic nodules and hepatocellular adenomas. Several new markers of hepatocellular differentiation have been described. These advances are reviewed.