Pathological diagnosis of liver cell adenoma, hepatocellular adenoma (HCA), and focal nodular hyperplasia (FNH) is discussed. HCA is a rare tumor, presenting in a variety of clinical settings, which cannot be identified conclusively by any currently available imaging technique. FNH has been reported in 0.6-3% of the general population and is 10 times more frequently observed than adenomas in referral centers. The examination of a liver biopsy or resection specimen remains the standard practice to establish the diagnosis of HCA and FNH when radiographic investigations have failed to establish a definitive diagnosis. The optimal care of patients with liver nodule requires the combined expertise of hepatologists, pathologists, radiologists, and surgeons. development of more readily available immunobiological tools will permit significant improvements in the liver biopsy interpretation in the ability to distinguish HCA and FNH.