Focal Nodular Hyperplasia : Intro & Clinical
Introduction: Focal nodular hyperplasia (FNH) is a tumor-like mass of benign hyperplastic hepatocytes surrounding a central stellate scar. It is not a true neoplasm but considered to be a regenerative response to local vascular anomalies. It is the 2nd most common benign liver nodule (after hemangioma). Clinical Features: FNH occurs over a wide age range but is most common in young women (3rd to 5th decades of life). Rare cases occur in children or men. Most cases are asymptomatic and discovered incidentally during upper abdominal imaging for unrelated reasons or for an enlarged liver. Large lesions may cause abdominal discomfort/pain due to compression of adjacent organs. Some cases are found during abdominal surgery or at autopsy. Hemoperitoneum is a rare complication. FNH is usually solitary. About 20% of cases are multicentric and may be associated with other vascular lesions, including cavernous hemangioma of the liver, portal vein thrombosis or atresia, Budd-Chiari syndrome, hereditary hemorrhagic telangiectasia, as well as neoplasms such as astrocytoma and meningioma. FNH is more common than hepatocellular adenoma and the two may coexist. Image courtesy of Dr. Jean-Christophe Fournet, Paris, France; humpath.com; Used with permission.