Fibrolamellar hepatocellular carcinoma arising in a background of focal nodular hyperplasia: a report of 2 cases.

BACKGROUND Fibrolamellar carcinoma, a rare variant of hepatocellular carcinoma, and focal nodular hyperplasia, a benign lesion, are rare hepatic lesions that are known to occur in young women with noncirrhotic livers. Some have suggested that fibrolamellar carcinoma might be the malignant counterpart of focal nodular hyperplasia. The coexistence of the 2 lesions is very rare. CASES Two cases of fibrolamellar hepatocellular carcinoma arising in a background of focal nodular hyperplasia followed long-term oral contraception, and 1 of the 2 occurred during pregnancy. CONCLUSION Distinguishing fibrolamellar carcinoma from focal nodular hyperplasia has important implications for treatment and prognosis. One should be aware of such conditions, especially in patients with a long history of oral contraception.