Benign tumors in the liver include hepatocellular adenomas, focal nodular hyperplasia, bile duct adenomas, and benign vascular lesions, all of which are often biopsied. Distinction of hepatocellular adenoma from carcinoma can be challenging on biopsy; the diagnosis of malignancy is aided by the reticulin stain which shows thickened cell plates and loss of reticulin. A malignancy diagnosis may also be aided by immunohistochemistry (IHC) staining.
