Hepatocellular Carcinoma Mimicking Focal Nodular Hyperplasia

Backround: 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 MRI- and CT-scans. Case series: We present a case series of three patients with solitary liver tumors which were highly suspicious to be large FNH, based on radiological features. 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 AFP in the third case. Histology revealed well to poor differentiated HCCs. Discussion: 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 uncertain diagnosis surgery should be offered to patients. Conclusion: In cases with a progression in size, an elevated level of AFP should be suspicious. A second opinion at a center for hepato-biliary surgery with HCC/FNH-experienced radiologists and surgeons is reasonable. 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.