Published online Apr 14, 2019. doi: 10.3748/wjg.v25.i14.1653
Peer-review started: February 14, 2019
First decision: March 5, 2019
Revised: March 12, 2019
Accepted: March 24, 2019
Article in press: March 25, 2019
Published online: April 14, 2019
Histopathologic diversity and several distinct histologic subtypes of hepatocellular carcinoma (HCC) are well-recognized. Recent advances in molecular pathology and growing knowledge about the biology associated with distinct histologic features and immuno-profile in HCC allowed pathologists to update classifications. Improving sub-classification will allow for more clinically relevant diagnoses and may allow for stratification into biologically meaningful subgroups. Therefore, immuno-histochemical and molecular testing are not only diagnostically useful, but also are being incorporated as crucial components in predicting prognosis of the patients with HCC. Possibilities of targeted therapy are being explored in HCC, and it will be important for pathologists to provide any data that may be valuable from a theranostic perspective. Herein, we review and provide updates regarding the pathologic sub-classification of HCC. Pathologic diagnostic approach and the role of biomarkers as prognosticators are reviewed. Further, the histopathology of four particular subtypes of HCC: Steatohepatitic, clear cell, fibrolamellar and scirrhous - and their clinical relevance, and the recent consensus on combined HCC-cholangiocarcinoma is summarized. Finally, emerging novel biomarkers and new approaches to HCC stratification are reviewed.
Core tip: We summarize the updated classifications of hepatocellular carcinoma. Immunohistochemistry and molecular pathology are becoming crucial components of prognostication and theranostics. Pathologic and molecular features of clinically relevant subtypes to include steatohepatitic, clear cell, fibrolamellar and scirrhous hepatocellular carcinomas are reviewed. Recent consensus on the combined hepatocellular carcinoma-cholangiocarcinoma, a controversial pathologic entity, is summarized.