Focal nodular hyperplasia of the liver.

The management of focal nodular hyperplasia (FNH) of the liver requires a systematic approach. After a histologic diagnosis of FNH is obtained, asymptomatic lesions can be observed safely with regular follow-up and treated if they become symptomatic or enlargement occurs. In the case presented here, we have elected follow-up with serial CT scans because our patient is asymptomatic and the lesion has not significantly enlarged. Patients who have symptomatic lesions while taking an oral contraceptive can have conservative follow-up when they stop taking the oral contraceptive, because regression of FNH has been reported to occur after cessation of oral contraceptive use. If the patient remains symptomatic or if the lesion enlarges after discontinuance of oral contraceptive use, surgical resection is warranted. Other symptomatic patients, including those with a previous history of taking oral contraceptives, should be treated by surgical resection or, when resection is not possible, by embolization or ligation of the hepatic artery, because symptomatic patients are at risk for having malignant lesions misdiagnosed as FNH.