Table 2.

Molecular findings, histological features, and immunohistochemical findings of FNH and HCA.

Item	FNH	H-HCA	IHCA	b-HCA
Molecular findings	Activation of the β-catenin pathway without mutations of CTNNB1	Biallelic mutations of HNF1A	Activation of the IL-6 signaling pathway due to mutations in IL6ST, FRK, STAT3, GNAS, and JAK1	Activation of the WNT signaling pathway due to mutation or deletion of CTNNB1
Histological features	Thick fibrous septa with or without a central scar, abnormal blood vessels, and ductular reaction	Prominent steatosis	Sinusoidal dilation, patchy inflammatory cell infiltration, and variable steatosis	Cellular and structural atypia and pseudoglands
Immunohistochemical findings
LFABP	(+)	(−)	(+)	(+)
β-catenin	Membranous	Membranous	Membranous	Nuclear
GS	Map-like	Patchy with perivascular accentuation	Patchy with perivascular accentuation	Diffuse homogenous or heterogenous staining depending on the mutation type
SAA/CRP	Usually (−)	(−)	Strong and diffuse	(−)
OATP1B3	(+)	(−)	(−)	(+)

b-HCA, β-catenin-activated HCA; CRP, C-reactive protein; FNH, focal nodular hyperplasia; GS, glutamine synthetase; HCA, hepatocellular adenoma; H-HCA, HNF1A-inactivated HCA; IHCA, inflammatory HCA; IL, interleukin; LFABP, liver fatty acid-binding protein; OATP, organic anion-transporting polypeptide; SAA, serum amyloid A; (+), positive; (−), negative.