How Molecular Discoveries Have Changed Liver Tumor Pathology: A Brief Review.

Context: Recent molecular discoveries have led to improved understanding of tumor biology and the development of new diagnostic assays.

Objective: To review primarily 3 examples of liver tumors and to briefly illustrate how recent molecular discoveries have altered clinical liver pathology practice.

Data sources: First, we will discuss fibrolamellar carcinoma, which will be the main focus of discussion, as an example for new diagnostic tests that have been developed as a result of molecular discoveries. Additional information on the role of molecular diagnostics in hepatocellular adenoma and hepatocellular carcinoma will be provided. Second, we will use the example of epithelioid hemangioendothelioma as an example of how new diagnostic tools, based on molecular discoveries, may support improved prognostication. Finally, we will use the example of intrahepatic cholangiocarcinoma as an example of a liver tumor where new molecular discoveries have identified tractable therapeutic targets and led to new effective therapies. This portion of the manuscript will also include a description of the anatomic and molecular differences between intrahepatic, hilar, and extrahepatic cholangiocarcinoma.

Conclusions: Fueled by molecular discoveries, new and better diagnostic tests and therapeutic targets have improved clinical care in patients affected by liver tumors.