Primary Liver Tumors Other than Hepatocellular Carcinoma: Clinical and Molecular Pearls

Purpose of Review: Liver tumors, excluding hepatocellular carcinoma and metastatic disease, are rare. However, it is important to understand how to distinguish these lesions from hepatocellular carcinoma. They run the spectrum of benign to malignant, some aggressive with relatively few therapeutic options. The goal of this paper is to review the most recent literature to provide current insights into diagnosis, treatment, and pathogenesis of these tumor types. Recent Findings: Recent literature has focused on oncogenomics and putative targets for therapeutic intervention. Several ongoing studies are elucidating molecular pathways and evaluating novel therapies in these rare tumors and we focus on these findings, particularly in intrahepatic cholangiocarcinoma and fibrolamellar HCC. While these advances are promising, surgical resection continues to be associated with the greatest survival benefit for rare malignant tumors of the liver. Summary: Clinicians must be aware of rare liver tumors to distinguish them from hepatocellular carcinoma and to develop a differential diagnosis in complicated or atypical presentations. In these rare tumors, advances in understanding tumor biology hold the promise of expanding diagnostic and therapeutic possibilities. © This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply 2018.