Atypical hepatic focal nodular hyperplasia presenting as acute abdomen and misdiagnosed as hepatocellular carcinoma.

Focal nodular hyperplasia (FNH) is a rare benign hepatic lesion, which is usually asymptomatic and solitary. Complications such as rupture and bleeding are extremely rare and only five cases have existed since 1975. We report a case of a 26-year-old woman with spontaneous rupture and hemorrhage of huge FNH presenting as acute abdomen. Different to previously recorded cases, this case was concomitant with multiple hepatic adenomas, which was misdiagnosed as rupture of hepatocellular carcinoma (HCC) with multiple intrahepatic spreading in another hospital. Our case highlights thepossible association between the size of FNH and the risk of rupture, and emphasizes the need to consider this in making treatment decisions. Although a conservative approach for asymptomatic FNH is well established, the potential for surgical intervention should always be considered, especially for large FNH. We recommend surgical resection of large FNH (>5 cm), symptomatic or not, rather than observation.