Focal Nodular Hyperplasia : Additional Image

The liver cell plates in focal nodular hyperplasia (FNH) are orderly and composed of mature, uniform hepatocytes with occasional mild cytologic atypia, enlarged nuclei, and mild hyperchromasia. Mitotic activity is very rare. FNH shows variable sinusoidal dilatation and scattered Kupffer cells (CD68+). With FNHs, there is no risk of malignant transformation and very low risk of complications such as hemoperitoneum. Many cases are left alone if they can be confidently diagnosed with imaging studies.