Hepatocellular adenomas: Magnetic resonance imaging features as a function of molecular pathological classification

Abstract

Hepatocellular adenomas (HCAs) are a group of benign tumors forming three molecular pathological subgroups: (1) hepatocyte nuclear factor 1␣ (HNF-1␣)-inactivated, (2) ␤-catenin-activated, and (3) inflammatory. Some HCAs present both ␤-catenin activation and inflammation. We analyzed magnetic resonance imaging (MRI) data for correlations between features on imaging and pathological classification of HCAs. We included 50 cases for which pathology specimens were classified into three groups based on immunohistochemical staining. Two characteristic MRI profiles were identified corresponding to HNF-1␣-inactivated and inflammatory HCAs. Fifteen HCAs were HNF-1␣-inactivated. The corresponding lesions showed (1) diffuse signal dropout on T1-weighted chemical shift sequence due to steatosis, (2) isosignal or slight hypersignal on T2-weighted (T2W) images, and (3) moderate enhancement in the arterial phase, with no persistent enhancement in the portal venous and delayed phases. For the diagnosis of HNF-1␣-inactivated HCA, the positive predictive value of homogeneous signal dropout on chemical shift images was 100%, the negative predictive value was 94.7%, the sensitivity was 86.7%, and the specificity was 100%. Twenty-three HCAs were inflammatory and showed (1) an absence or only focal signal dropout on chemical shift sequence; (2) marked hypersignal on T2W sequences, with a stronger signal in the outer part of the lesions, correlating with sinusoidal dilatation areas; and (3) strong arterial enhancement, with persistent enhancement in the portal venous and delayed phases. Marked hypersignal on T2W sequences associated with delayed persistent enhancement had a positive predictive value of 88.5%, a negative predictive value of 84%, a sensitivity of 85.2%, and a specificity of 87.5% for the diagnosis of inflammatory HCA. Conclusion: HNF-1␣-mutated HCAs and inflammatory HCAs were associated with specific MRI patterns related to diffuse fat repartition and sinusoidal dilatation, respectively. (HEPATOLOGY 2008;48:808-818.) H epatocellular adenoma (HCA) is a rare type of benign monoclonal liver neoplasm, occurring mostly in young women using oral contraceptives. Several molecular features associated with HCA have recently been described (for review, see Rebouissou et al. 1 ).Biallelic-inactivating mutations of the TCF1 gene inactivating hepatocyte nuclear factor 1␣ (HNF-1␣) have been identified in 35% to 50% of HCAs. 2-4 Furthermore, HCAs harboring HNF-1␣ mutations have been shown to display repressed gluconeogenesis, together with activa-

Defects in MAP1S‐mediated autophagy cause reduction in mouse lifespans especially when fibronectin is overexpressed

“…Autophagy defects lead to enhancement of oxidative stresses and promotion of inflammation and pyroptosis (Mizushima et al ., 1998; Liu et al ., 2012; Lamkanfi & Dixit, 2014). Sinusoidal dilatation is a type of vascular liver lesions previously reported to be associated with inflammatory hepatocellular adenoma (formerly known as telangiectatic focal nodular hyperplasia) (Laumonier et al ., 2008). It is characterized by widening of hepatic capillaries and may impair their contractile properties (Saadoun et al ., 2004).…”

Hepatic adenomatosis: MR Imaging Features

“…These different subtypes show variable clinical behaviour, imaging findings, and natural history, and thus the options for treatment surveillance may vary (7). The MRI findings of different subtypes of hepatocellular adenomas have been reported by Laumonier et al (11). HNF-1alpha-mutated hepatocellular adenomas and inflammatory hepatocellular adenomas have been described to be associated with specific MRI patterns and related to diffuse fat distribution and to sinusoidal dilatation, respectively.…”

“…After gadolinium-based contrast material administration moderate enhancement is noted in the arterial phase, with absence of persistent enhancement in the portal venous and delayed phases (7,11). A homogeneous signal drop-off on chemical shift images for the diagnosis of HNF-1alpha-mutated hepatocellular adenomas has been shown a sensitivity and specificity of 86% and 100% respectively (11). No specific MRI imaging features have been described for the diagnosis betacatenin-mutated hepatocellular adenomas.…”

“…With extracellular gadolinium-based contrast media strong arterial enhancement that may or may not persist on the portal venous and delayed phases can be seen. Beta-catenin-mutated hepatocellular adenomas may mimic hepatocellular carcinoma (7,11).…”

“…After intravenous administration of gadolinium-based contrast material intense enhancement during the arterial phase is seen, with persistent enhancement in the portal venous and delayed phases (7,11). A marked T2 hyperintensity together with delayed persistent enhancement for the diagnosis of inflammatory hepatocellular adenomas has been reported to correspond with a sensitivity of 85% and a specificity of 87% (11). HNF-1alpha-mutated hepatocellular adenomas are are isoinpatients (3).…”