BENIGN NEOPLASMS



The group of benign neoplastic lesions includes hepatocellular adenoma, focal nodular hyperpla­sia, hemangioma, bile duct adenoma, and other rare tumors of mesenchymal origin (e.g., fibromas, lipomas, leiomyomas). Hepatocellular adenomas occur almost exclusively in women, and there is strong circumstantial evidence to implicate estro­gens, especially oral contraceptives, in their de­velopment and growth. Adenomas consist of a monotonous array of normal hepatocytes without bile ducts, portal tracts, orKupffer cells. Although they are not regarded as premalignant lesions, they have a predilection for hemorrhage, tumor infarct, and rupture. Patients usually present with signs and symptoms of an abdominal mass or hemorrhage (pain, fever, circulatory collapse). The latter individuals usually require emergency surgery and resection of the adenoma.

Adenomas usually appear as cold spots on 99mTc-sulfur colloid scans and as vascular lesions on angiography. Management of asymptomatic le­sions is controversial, although elective surgical excision is usually performed. A trial period of observation may be warranted if oral contracep­tives can be discontinued, and some adenomas have been noted to regress under this regimen.