Focal Nodular Hyperplasia : Microscopic

Microscopic Features: Focal nodular hyperplasia (FNH) comprises nodules of normal-appearing hepatocytes, which are partially separated by the fibrous bands that radiate from the central fibrous zone. There is some resemblance to cirrhosis. The fibrovascular stroma contains thick-walled dystrophic arteries, bile ductular proliferations, and inflammatory infiltrates. FNH lacks normal portal tracts but, rarely, there may be intermediate- to large-caliber bile ducts within the central fibrous zone.