Table 4.

Clinicopathologic and imaging characteristic of fibrolamillar hepatocellular carcinoma in comparison to focal nodular hyperplasia and hepatocellular adenoma [21, 35–45, 70–72]

Lesion Characteristics	FL-HCC	FNH	HCA
Entity	Malignant	Benign, mainly proliferating normal hepatocytes	Benign with the potential to malignant transformation
Location	Anywhere in the liver	Frequently in the periphery	Anywhere in the liver
Size and number	Single, large, and lobulated	Single or multiple, small in size	Single or multiple, small in size
Sex predilection	No	Otherwise healthy young women	Otherwise healthy young women
Causal relationship to oral contraception (OC)	Not known	Not known	Yes
Main findings on imaging	CT: large tumor, heterogeneous hypervascular enhancement MRI: Large tumor, hypointense on T1-weighted and hyperintense on T2-weighted images, T2 hypointense central scare, no fat component, hyperattenuating on the arterial phase, hypo-, iso-, or even hyperattenuating in venous phases	CT: arterial enhancement, presence of central scare MRI: arterial enhancement, central scare predominantly T2 hyperintense, homogeneous signal intensity, accumulation of liver-specific contrast agent within the central area on delayed T1 images	CT: arterial enhancement, precontrast hyperdense areas showing hemorrhage, low-density areas showing necrosis or fat MRI: arterial enhancement, hyperintense areas on T1, T2 images showing hemorrhage, hypointense areas on T1 that correlate to hyperintense areas on T2 images showing necrosis, no accumulation of liver-specific contrast agent within the lesion
Treatment	Surgical	Normally requires no treatment	Discontinuation of OC, surgical

FL-HCC fibrolamellar hepatocellular carcinoma, FNH focal nodular hyperplasia, HCA hepatocellular adenoma, CT computed tomography, MRI magnetic resonance imaging