Hepatocellular carcinoma mimicking focal nodular hyperplasia

Abstract

Focal nodular hyperplasia (FNH) is a common benign liver lesion, mostly solitary, and with no evidence of malignant transformation over time. The diagnosis can usually be made by imaging modalities with distinct features in magnetic resonance imaging (MRI) and computed tomography (CT) scans. We present a case series of three patients with solitary liver tumors which were, based on radiological features, first diagnosed to be large FNH. The patients were sent to our center for second opinion and probable treatment. Indication for resection was given because of nonconclusive radiologic imaging in the first, substantial growth progression in the second and elevated alpha fetoprotein (AFP) in the third case. Histology revealed well to poor differentiated hepatocellular carcinoma (HCC). FNH tends to show a distinct pattern in imaging modalities, but HCC can mimic FNH. The MRI-scan using hepatotropic contrast agent is the most sensitive imaging modality to diagnose FNH. AFP is usually not elevated in FNH. Asymptomatic FNH does not require surgery but a reliable diagnosis is crucial. In case of an un-certain diagnosis surgery should be offered to patients. In cases with a progression in size, an elevated level of AFP should be suspicious. Generally, an over-therapy via surgery should be avoided and follow-ups of a newly diagnosed FNH including measurement of AFP are advisable to detect alterations.