Hepatic mass lesions: challenges and pitfalls

Though commonly encountered in clinical practice, hepatic mass lesions can present myriad diagnostic challenges, especially in needle biopsy specimens. Familiarity with the various pitfalls and caveats of morphologic evaluation and ancillary staining will likely improve both diagnostic accuracy and clinical outcomes. Herein, we discuss common hepatic mass lesions, including focal nodular hyperplasia, hepatic adenoma (and subtypes), variants of hepatocellular carcinoma, cirrhotic nodules (regenerative and dysplastic), segmental atrophy of the liver, and selected biliary lesions often seen in biopsy and resection specimens.