Evaluating Liver Biopsies with Well-Differentiated Hepatocellular Lesions

Needle core biopsies of liver lesions can be challenging, particularly in cases with limited material. The differential diagnosis for well-differentiated hepatocellular lesions includes focal nodular hyperplasia, hepatocellular adenoma, and well-differentiated hepatocellular carcinoma (HCC) in noncirrhotic liver, while dysplastic nodules and well-differentiated HCC are the primary considerations in cirrhotic liver. The first part of this review focuses on histochemical and immunohistochemical stains as well as molecular assays that are useful in the differential diagnosis. The second portion describes the features of hepatocellular adenoma subtypes and focuses on the differential diagnoses in commonly encountered clinicopathologic scenarios.