Estrobolome and Hepatocellular Adenomas-Connecting the Dots of the Gut Microbial ß-Glucuronidase Pathway as a Metabolic Link.

Hepatocellular adenomas are benign endothelial tumors of the liver, mostly associated with female individual users of estrogen-containing medications. However, the precise factors underlying the selective development of hepatic adenomas in certain females remain elusive. Additionally, the conventional profile of individuals prone to hepatic adenoma is changing. Notably, male patients exhibit a higher risk of malignant progression of hepatocellular adenomas, and there are instances where hepatic adenomas have no identifiable cause. In this paper, we theorize the role of the human gastrointestinal microbiota, specifically, of bacterial species producing ß-glucuronidase enzymes, in the development of hepatic adenomas through the estrogen recycling pathway. Furthermore, we aim to address some of the existing gaps in our knowledge of pathophysiological pathways which are not yet subject to research or need to be studied further. As microbial ß-glucuronidases proteins recycle estrogen and facilitate the conversion of inactive estrogen into its active form, this process results in elevated levels of unbound plasmatic estrogen, leading to extended exposure to estrogen. We suggest that an imbalance in the estrobolome could contribute to sex hormone disease evolution and, consequently, to the advancement of hepatocellular adenomas, which are estrogen related.

CRP Versus SAA for Identification of Inflammatory Hepatic Adenomas.

Subtyping hepatic adenomas is important for patient management due to differing complication risks. Immunohistochemical staining with C-reactive protein (CRP) and serum amyloid-A (SAA) is widely accepted as a surrogate for molecular classification to identify inflammatory hepatocellular adenomas. Limited data, however, has been published on how these 2 stains compare for sensitivity. We conducted a large, multicenter, retrospective study to examine the sensitivity and staining characteristics of CRP and SAA in inflammatory hepatic adenomas, with focal nodular hyperplasia (FNHs) as a control group. Inflammatory adenomas were identified in 133 patients (average age 37 years, 109 were female). In all, 69.9% of cases were resection specimens and 90.2% of all cases showed positive staining for both CRP and SAA; 10 (7.5%) were positive for CRP only and 3 (2.3%) were positive for SAA only. CRP was more sensitive than SAA (97.74% vs. 92.48%, P -value = 0.0961) and showed more extensive and intense staining, with a significantly higher modified H-score ( P <0.001). Focal nodular hyperplasia can also show positive CRP and SAA staining but with a lower modified H-score ( P <0.0001). Based on beta-catenin and glutamine synthetase staining, 26 of inflammatory adenomas also had beta-catenin activation (19.5%). All 3 cases with positive SAA and negative CRP staining were beta-catenin activated. In contrast, the proportion of cases that were CRP positive and SAA negative was similar regardless of beta-catenin activation. The data affirms the strategy of using both CRP and SAA immunostains for hepatic adenoma subtyping and raises the awareness of the highly variable nature of SAA staining characteristics.

SEPT9 Expression in Hepatic Nodules: An Immunohistochemical Study of Hepatocellular Neoplasm and Metastasis.

The methylated SEPT9 DNA ( mSEPT9 ) in plasma is a US Food and Drug Administration (FDA)-approved screening biomarker in colorectal cancer and is emerging as a promising diagnostic and prognostic biomarker in hepatocellular carcinoma (HCC). We evaluated the SEPT9 protein expression by immunohistochemistry (IHC) in various hepatic tumors from 164 hepatectomies and explants. Cases diagnosed as HCC (n=68), hepatocellular adenoma (n=31), dysplastic nodule (n=24), and metastasis (n=41) were retrieved. SEPT9 stain was performed on representative tissue blocks showing tumor/liver interface. For HCC, archived IHC (SATB2, CK19, CDX2, CK20, and CDH17) slides were also reviewed. The findings were correlated with demographics, risk factors, tumor size, alpha fetoprotein levels at diagnosis, T stage and oncologic outcomes, with significance defined as P <0.05. Percentage of SEPT9 positivity differed significantly among hepatocellular adenoma (3%), dysplastic nodule (0%), HCC (32%), and metastasis (83%, P <0.001). Compared with patients with SEPT9- HCC, those with SEPT9+ HCC were older (70 vs. 63 y, P =0.01). The extent of SEPT9 staining correlated with age ( rs =0.31, P =0.01), tumor grade ( rs =0.30, P =0.01), and extent of SATB2 staining ( rs =0.28, P =0.02). No associations were found between SEPT9 staining and tumor size, T stage, risk factors, CK19, CDX2, CK20, or CDH17 expression, alpha fetoprotein levels at diagnosis, METAVIR fibrosis stage, and oncologic outcome in the HCC cohort. SEPT9 is likely implicated in liver carcinogenesis in a HCC subset. Similar to mSEPT9 DNA measurement in liquid biopsies, SEPT9 staining by IHC may prove helpful as an adjunct diagnostic biomarker with potential prognostic ramifications.

Spontaneous Occurrence of Various Types of Hepatocellular Adenoma in the Livers of Metabolic Syndrome-Associated Steatohepatitis Model TSOD Mice.

Male Tsumura-Suzuki Obese Diabetes (TSOD) mice, a spontaneous metabolic syndrome model, develop non-alcoholic steatohepatitis and liver tumors by feeding on a standard mouse diet. Nearly 70% of liver tumors express glutamine synthetase (GS), a marker of hepatocellular carcinoma. In contrast, approximately 30% are GS-negative without prominent nuclear or structural atypia. In this study, we examined the characteristics of the GS-negative tumors of TSOD mice. Twenty male TSOD mice were sacrificed at 40 weeks and a total of 21 tumors were analyzed by HE staining and immunostaining of GS, liver fatty acid-binding protein (L-FABP), serum amyloid A (SAA), and beta-catenin. With immunostaining for GS, six (29%) tumors were negative. Based on the histological and immunohistological characteristics, six GS-negative tumors were classified into several subtypes of human hepatocellular adenoma (HCA). One large tumor showed generally similar findings to inflammatory HCA, but contained small atypical foci with GS staining and partial nuclear beta-catenin expression suggesting malignant transformation. GS-negative tumors of TSOD mice contained features similar to various subtypes of HCA. Different HCA subtypes occurring in the same liver have been reported in humans; however, the diversity of patient backgrounds limits the ability to conduct a detailed, multifaceted analysis. TSOD mice may share similar mechanisms of HCA development as in humans. It is timely to review the pathogenesis of HCA from both genetic and environmental perspectives, and it is expected that TSOD mice will make further contributions in this regard.

Vitamin D3 supplementation alleviates chemically-induced cirrhosis-associated hepatocarcinogenesis.

Vitamin D3 (VD3) deficiency has been associated with increased risk for cirrhosis and hepatocellular carcinoma, a highly incident malignant neoplasia worldwide. On the other hand, VD3 supplementation has shown some beneficial effects in clinical studies and rodent models of chronic liver disease. However, preventive effects of dietary VD3 supplementation in cirrhosis-associated hepatocarcinogenesis is still unknow. To investigate this purpose, male Wistar rats submitted to a combined diethylnitrosamine- and thioacetamide-induced model were concomitantly supplemented with VD3 (5,000 and 10,000 IU/kg diet) for 25 weeks. Liver samples were collected for histological, biochemical and molecular analysis. Serum samples were used to measure 25-hydroxyvitamin D [25(OH)D] and alanine aminotransferase levels. Both VD3 interventions decreased hepatic collagen deposition and pro-inflammatory p65 protein levels, while increased hepatic antioxidant catalase and glutathione peroxidase activities and serum 25(OH)D, without a clear dose-response effect. Nonetheless, only the highest concentration of VD3 increased hepatic protein levels of VD receptor, while decreased the number of large preneoplastic glutathione-S-transferase- (>0.5 mm²) and keratin 8/18-positive lesions, as well the multiplicity of hepatocellular adenomas. Moreover, this intervention increased hepatic antioxidant Nrf2 protein levels and glutathione-S-transferase activity. In summary, dietary VD3 supplementation - in special the highest intervention - showed antifibrotic and antineoplastic properties in chemically-induced cirrhosis-associated hepatocarcinogenesis. The positive modulation of Nrf2 antioxidant axis may be mechanistically involved with these beneficial effects, and may guide future clinical studies.

Application of Immunohistochemistry in the Pathological Diagnosis of Liver Tumors.

Although radiological diagnostics have been progressing, pathological diagnosis remains the most reliable method for diagnosing liver tumors. In some cases, definite pathological diagnosis cannot be obtained by histological evaluation alone, especially when the sample is a small biopsy; in such cases, immunohistochemical staining is very useful. Immunohistochemistry is the most frequently used technique for molecular pathological diagnosis due to its broad application, ease of performance and evaluation, and reasonable cost. The results occasionally reflect specific genetic mutations. The immunohistochemical markers of hepatocellular carcinoma include those of hepatocellular differentiation-such as hepatocyte paraffin 1 and arginase-1-and those of malignant hepatocytes-such as glypican-3, heat shock protein 70, and glutamine synthetase (GS). To classify the subtypes of hepatocellular adenoma, examination of several immunohistochemical markers, such as liver fatty acid-binding protein, GS, and serum amyloid A, is indispensable. Immunohistochemical staining for GS is also important for the diagnosis of focal nodular hyperplasia. The representative immunohistochemical markers of intrahepatic cholangiocarcinoma include cytokeratin (CK) 7 and CK19. In this article, we provide an overview of the application of immunohistochemistry in the pathological diagnosis of liver tumors referring to the association with genetic alterations. Furthermore, we aimed to explain the practical points in the differential diagnosis of liver tumors by immunohistochemical staining.

Proteomic Profiling of Hepatocellular Adenomas Paves the Way to Diagnostic and Prognostic Approaches.

BACKGROUND AND AIMS: Through an exploratory proteomic approach based on typical hepatocellular adenomas (HCAs), we previously identified a diagnostic biomarker for a distinctive subtype of HCA with high risk of bleeding, already validated on a multicenter cohort. We hypothesized that the whole protein expression deregulation profile could deliver much more informative data for tumor characterization. Therefore, we pursued our analysis with the characterization of HCA proteomic profiles, evaluating their correspondence with the established genotype/phenotype classification and assessing whether they could provide added diagnosis and prognosis values. APPROACH AND RESULTS: From a collection of 260 cases, we selected 52 typical cases of all different subgroups on which we built a reference HCA proteomics database. Combining laser microdissection and mass-spectrometry-based proteomic analysis, we compared the relative protein abundances between tumoral (T) and nontumoral (NT) liver tissues from each patient and we defined a specific proteomic profile of each of the HCA subgroups. Next, we built a matching algorithm comparing the proteomic profile extracted from a patient with our reference HCA database. Proteomic profiles allowed HCA classification and made diagnosis possible, even for complex cases with immunohistological or genomic analysis that did not lead to a formal conclusion. Despite a well-established pathomolecular classification, clinical practices have not substantially changed and the HCA management link to the assessment of the malignant transformation risk remains delicate for many surgeons. That is why we also identified and validated a proteomic profile that would directly evaluate malignant transformation risk regardless of HCA subtype. CONCLUSIONS: This work proposes a proteomic-based machine learning tool, operational on fixed biopsies, that can improve diagnosis and prognosis and therefore patient management for HCAs.

HBP-enhancing hepatocellular adenomas and how to discriminate them from FNH in Gd-EOB MRI.

BACKGROUND: Recent studies provide evidence that hepatocellular  adenomas  (HCAs) frequently take up gadoxetic acid (Gd-EOB) during the hepatobiliary phase (HBP). The purpose of our study was to investigate how to differentiate between Gd-EOB-enhancing HCAs and focal nodular hyperplasias (FNHs). We therefore retrospectively included 40 HCAs classified as HBP Gd-EOB-enhancing lesions from a sample of 100 histopathologically proven HCAs in 65 patients. These enhancing HCAs were matched retrospectively with 28 FNH lesions (standard of reference: surgical resection). Two readers (experienced abdominal radiologists blinded to clinical data) reviewed the images evaluating morphologic features and subjectively scoring Gd-EOB uptake (25-50%, 50-75% and 75-100%) for each lesion. Quantitative lesion-to-liver enhancement was measured in arterial, portal venous (PV), transitional and HBP. Additionally, multivariate regression analyses were performed. RESULTS: Subjective scoring of intralesional Gd-EOB uptake showed the highest discriminatory accuracies (AUC: 0.848 (R#1); 0.920 (R#2)-p < 0.001) with significantly higher uptake scores assigned to FNHs (Cut-off: 75%-100%). Typical lobulation and presence of a central scar in FNH achieved an accuracy of 0.750 or higher in at least one reader (lobulation-AUC: 0.809 (R#1); 0.736 (R#2); central scar-AUC: 0.595 (R#1); 0.784 (R#2)). The multivariate regression emphasized the discriminatory power of the Gd-EOB scoring (p = 0.001/OR:22.15 (R#1) and p < 0.001/OR:99.12 (R#2). The lesion-to-liver ratio differed significantly between FNH and HCA in the PV phase and HBP (PV: 132.9 (FNH) and 110.2 (HCA), p = 0.048 and HBP: 110.3 (FNH) and 39.2 (HCA), p < 0.001)), while the difference was not significant in arterial and transitional contrast phases (p > 0.05). CONCLUSION: Even in HBP-enhancing HCA, characterization of Gd-EOB uptake was found to provide the strongest discriminatory power in differentiating HCA from FNH. Furthermore, a lobulated appearance and a central scar are more frequently seen in FNH than in HCA.

Hepatocellular adenomas: is there additional value in using Gd-EOB-enhanced MRI for subtype differentiation?

PURPOSE: To differentiate subtypes of hepatocellular adenoma (HCA) based on enhancement characteristics in gadoxetic acid (Gd-EOB) magnetic resonance imaging (MRI). MATERIALS AND METHODS: Forty-eight patients with 79 histopathologically proven HCAs who underwent Gd-EOB-enhanced MRI were enrolled (standard of reference: surgical resection). Two blinded radiologists performed quantitative measurements (lesion-to-liver enhancement) and evaluated qualitative imaging features. Inter-reader variability was tested. Advanced texture analysis was used to evaluate lesion heterogeneity three-dimensionally. RESULTS: Overall, there were 19 (24%) hepatocyte nuclear factor (HNF)-1a-mutated (HHCAs), 37 (47%) inflammatory (IHCAs), 5 (6.5%) b-catenin-activated (bHCA), and 18 (22.5%) unclassified (UHCAs) adenomas. In the hepatobiliary phase (HBP), 49.5% (39/79) of all adenomas were rated as hypointense and 50.5% (40/79) as significantly enhancing (defined as > 25% intralesional GD-EOB uptake). 82.5% (33/40) of significantly enhancing adenomas were IHCAs, while only 4% (1/40) were in the HHCA subgroup (p < 0.001). When Gd-EOB uptake behavior was considered in conjunction with established MRI features (binary regression model), the area under the curve (AUC) increased from 0.785 to 0.953 for differentiation of IHCA (atoll sign + hyperintensity), from 0.859 to 0.903 for bHCA (scar + hyperintensity), and from 0.899 to 0.957 for HHCA (steatosis + hypointensity). Three-dimensional region of interest (3D ROI) analysis showed significantly increased voxel heterogeneity for IHCAs (p = 0.038). CONCLUSION: Gd-EOB MRI is of added value for subtype differentiation of HCAs and reliably identifies the typical heterogeneous HBP uptake of IHCAs. Diagnostic accuracy can be improved significantly by the combined analysis of established morphologic MR appearances and intralesional Gd-EOB uptake. KEY POINTS: •Gd-EOB-enhanced MRI is of added value for subtype differentiation of HCA. •IHCA and HHCA can be identified reliably based on their typical Gd-EOB uptake patterns, and accuracy increases significantly when additionally taking established MR appearances into account. •The small numbers of bHCAs and UHCAs remain the source of diagnostic uncertainty.

Does Argininosuccinate Synthase 1 (ASS1) Immunohistochemistry Predict an Increased Risk of Hemorrhage for Hepatocellular Adenomas?

Hepatocellular adenomas (HCAs) often pursue an innocuous clinical course. Recent work has elucidated important subtypes of HCA and biomarkers to identify them, including HCA at an increased risk for malignant transformation. Another key complication of HCAs is the risk of spontaneous tumoral hemorrhage, which may be life-threatening. Identification of a predictive biomarker for this clinical complication would therefore be of clinical value. It has been suggested that Argininosuccinate Synthase 1 (ASS1) immunohistochemistry (IHC) identifies HCA with a high propensity for hemorrhage. The aim of our study was to validate ASS1 IHC as a predictive marker of hemorrhage. Eighty-nine HCAs were collected for ASS1 IHC and subtyped according to published criteria. Clinical records were examined for evidence of tumoral hemorrhage. Twenty-one (23.6%) HCAs were complicated by clinically detected hemorrhage and were more likely to be resected (P=0.0002). Hemorrhage complicated all WHO subtypes of HCA. There was no association between hemorrhage and HCA subtype (P=0.92). Neither the distribution of ASS1 expression nor the intensity of ASS1 expression compared to normal liver showed a significant association with hemorrhage (P=0.051 and 0.34). Interlaboratory comparison of 8 cases showed good agreement regarding the intensity (6/8 and 7/8) and distribution of staining (7/8 and 7/8) across 3 laboratories performing ASS1 IHC. In conclusion, all subtypes of HCA may be complicated by hemorrhage. ASS1 IHC expression did not correlate with hemorrhagic complications. Caution is prudent before routine implementation of ASS1 IHC in clinical practice.

Iso- or hyperintensity of hepatocellular adenomas on hepatobiliary phase does not always correspond to hepatospecific contrast-agent uptake: importance for tumor subtyping.

PURPOSE: This study was conducted in order to evaluate if iso- or hyperintensity of HCAs on HBP is systematically related to a high uptake of hepatospecific contrast agent, using a quantitative approach. METHODS: This bicentric retrospective study included all patients with histologically confirmed and subtyped HCA from 2009 to 2017 who underwent MRI with HBP after Gd-BOPTA injection and who showed iso- or hyperintensity on HBP. The signal intensity of tumors on pre- and postcontrast images and the presence of hepatic steatosis were noted. Contrast uptake on HBP was quantified using the liver-to-lesion contrast enhancement ratio (LLCER) and compared between HCA subtypes (Wilcoxon signed-rank test). Categorical variables were compared using chi-square tests. RESULTS: Twenty-four HCAs showed iso- or hyperintensity on HBP, specifically 17 inflammatory (IHCAs) and 7 ß-catenin HCAs (BHCAs). Eighteen HCAs (75%) (17 IHCAs and 1 BHCAs) had a LLCER < 0% (median - 13.6%, group 1), of which 94% were hyperintense on precontrast T1-W images, with background hepatic steatosis. Six HCAs (25%) had LLCER ≥ 0% (median 2.9%, group 2), and all were BHCAs. A LLCER ≥ 1.6% was associated with the diagnosis of BHCA with a sensitivity of 86% and a specificity of 100%. CONCLUSION: In conclusion, iso- or hyperintensity of hepatocellular adenomas on HBP does not necessarily correspond to an increased hepatospecific contrast-agent uptake. In IHCA, tumor hyperintensity on precontrast images and the underlying steatosis likely explain such iso- or hyperintensity, which do show reduced HBP contrast-agent uptake. On the other hand, marked contrast uptake can be observed, especially in BHCA. KEY POINTS: • Iso- or hyperintensity on HBP does not necessarily reflect a high uptake of hepatospecific contrast agent. • Discrepancies between qualitative signal intensity and quantitative hepatospecific contrast uptake can be explained in IHCA by a combination of tumor hyperintensity on precontrast images and underlying hepatic steatosis. • In BHCA, iso- or hyperintensity on HBP does actually correspond to a greater contrast uptake than that of the liver, demonstrated by an increased lesion-to-liver contrast enhancement ratio (LLCER).

Development and Validation of a Model to Predict Regression of Large Size Hepatocellular Adenoma.

INTRODUCTION: Surgery is advocated in hepatocellular adenomas (HCA) >5 cm that do not regress to <5 cm after 6-12 months. The aim of this study was to develop a model for these patients, estimating the probability of HCA regression to <5 cm at 1 and 2 years follow-up. METHODS: Data were derived from a multicenter retrospective cohort of female patients diagnosed with HCA >5 cm at first follow-up. Potential predictors included age, body mass index, and HCA diameter at diagnosis (T0), HCA-subtype (hepatocyte nuclear factor 1α inactivated HCA, inflammatory-HCA, unclassified HCA) and "T0-T1 regression-over-time" (percentage of regression between T0 and first follow-up (T1) divided by weeks between T0 and T1). Cox proportional hazards regression was used to develop a multivariable model with time to regression of HCA < 5 cm as outcome. Probabilities at 1 and 2 years follow-up were calculated. RESULTS: In total, 180 female patients were included. Median HCA diameter at T0 was 82.0 mm and at T1 65.0 mm. Eighty-one patients (45%) reached the clinical endpoint of regression to <5 cm after a median of 34 months. No complications occurred during follow-up. In multivariable analysis, the strongest predictors for regression to <5 cm were HCA diameter at T0 (logtransformed, hazard ratio (HR) 0.05), T0-T1 regression-over-time (HR 2.15) and HCA subtype inflammatory-HCA (HR 2.93) and unclassified HCA (HR 2.40), compared to hepatocyte nuclear factor 1α inactivated HCA (reference). The model yielded an internally validated c-index of 0.79. DISCUSSION: In patients diagnosed with HCA > 5 cm that still exceed 5 cm at first follow-up, regression to <5 cm can be predicted at 1 and 2 years follow-up using this model. Although external validation in an independent population is required, this model may aid in decision-making and potentially avoid unnecessary surgery.

Utilization of spectrins ßI and ßIII in diagnosis of hepatocellular carcinoma.

Spectrins are a group of cytoskeletal proteins which participate in many important cellular functions. It has been suggested that loss of spectrin isoforms may be associated with tumorigenesis of lymphoma, leukemia, gastric cancer and hepatocellular carcinoma (HCC). We recently reported that ßI spectrin expression was present in normal hepatocytes but lost in HCC cells, which suggested that spectrins may be helpful markers in diagnosis of HCC. In this study, using immunohistochemical staining, we further investigated the expression pattern of four spectrin isoforms (αII, ßI-III) on different benign and malignant liver tumors including focal nodular hyperplasia (FNH), hepatic adenoma (HA), HCC, and cholangiocarcinoma (CC). The results revealed that ßI spectrin was moderately to strongly positive in FNH and HA tissues, but was only weakly positive or lost in HCC cases and was weakly positive in all CC cases. In addition, the ßIII spectrin, majority of which was moderately positive in both FNH and HA tissues, was mostly lost in poorly differentiated HCC but remained at least moderately positive in most CC cases. These results suggest that spectrins ßI and ßIII may be used to differentiate well differentiated HCC from FNH or HA, and poorly differentiated HCC from CC, respectively.

Quantitative correlation between uptake of Gd-BOPTA on hepatobiliary phase and tumor molecular features in patients with benign hepatocellular lesions.

PURPOSE: The purpose of our study was to correlate the quantitative analysis of benign hepatocellular tumor uptake on delayed hepatobiliary phase (HBP) imaging with the quantitative level of OATP expression. METHODS: This single-center retrospective study, which took place between September 2009 and March 2015, included 20 consecutive patients with a proven pathologic and immunohistochemical (IHC) diagnosis of FNH or HCA, including quantification of the OATP expression. The patients underwent Gd-BOPTA-enhancement MRI, including an HBP. The analysis of HBP uptake was performed using the liver-to-lesion contrast enhancement ratio (LLCER). Mean LLCER and OATP expressions were compared between FNH and HCA, and the expression of OATP was correlated with the LLCER value. RESULTS: Of the 23 benign hepatocellular tumors, 9 (39%) were FNH and 14 (61%) were HCA, including 6 inflammatory, 2 HNF1a inactivated, 3 ß-catenin-mutated and 3 unclassified HCAs. On HBP, 100% of the FNH appeared hyper- or isointense, and 79% of the adenomas appeared hypointense. The mean OATP expression of FNH (46.67 ± 26.58%) was significantly higher than that of HCA (22.14 ± 30.74%) (p = 0.0273), and the mean LLCER of FNH (10.66 ± 7.403%) was significantly higher than that of HCA (-13.5 ± 12.25%) (p < 0.0001). The mean LLCER of ß-catenin-mutated HCA was significantly higher than that of other HCAs (p = 0.011). Significant correlation was found between the OATP expression and LLCER values (r = 0.661; p = 0.001). CONCLUSION: In benign hepatocellular tumors, the quantitative analysis of hepatobiliary contrast agent uptake on HBP is correlated with the level of OATP expression and could be used as an imaging biomarker of the molecular background of HCA and FNH. KEY POINTS: • Gd-BOPTA uptake on HBP correlates with the OATP level in benign hepatocellular tumors • FNH and ß-catenin-mutated HCA showed an increased lesion-to-liver contrast enhancement ratio (LLCER) • Increased LLCER may be explained by activation of the Wnt ß-catenin pathway.

Copper deposition in focal nodular hyperplasia and inflammatory hepatocellular adenoma.

AIMS: To examine copper deposition in focal nodular hyperplasia (FNH) and inflammatory hepatocellular adenoma (IHA) and to determine if it can play a role in their differentiation. METHODS: 28 FNHs and 19 IHAs from surgical resections showing typical morphological and immunohistochemical features were stained with rhodanine to evaluate for copper deposition. Histological features such as nodularity, fibrous bands, ductular proliferation, steatosis, ballooned hepatocytes and lymphocytic inflammation were also scored. RESULTS: Copper deposition was detected in 96% (27/28) of FNHs and 37% (7/19) of IHAs, P<0.001. In all cases, copper was seen within the hepatocytes only around the pseudo-portal tracts or areas of fibrosis. Copper deposition in IHA was significantly associated with presence of lymphocytic inflammation (P=0.04) but not associated with features like nodularity, fibrous bands, ductular proliferation, ballooned hepatocytes and steatosis (P>0.05, for all). In FNH, the presence and degree of copper deposition was not significantly associated with any histological features (P>0.05, for all). CONCLUSIONS: Copper deposition occurs more frequently in FNH (96%) than IHA (37%), P<0.001. However, the presence of copper alone cannot be used as a feature to differentiate between FNH and IHA.

Incidental inflammatory adenoma with ß-catenin activation in the setting of paediatric NASH.

Hepatocellular adenomas (HCA) are benign tumours with potential for malignant transformation with no recommendations regarding management in the paediatric population. We report a case of an inflammatory adenoma with ß-catenin activated pathway in an obese, paediatric patient with nonalcoholic steatohepatitis (NASH). CASE REPORT: An 11-year-old female presented with a microlobulated liver lesion measuring >5 cm in magnetic resonance imaging (MRI) with inflammatory adenoma with ß-catenin activated pathology arising in a background of NASH, nonalcoholic fatty liver disease (NAFLD) activity score 5/8. Imaging follow-up demonstrated stable disease without progression for 3 years. DISCUSSION: Malignant transformation of Hepatocellular adenomas in a child is approximately 4.2%. It is unknown if hepatic steatosis increases this risk. Obese patients mainly develop inflammatory and ß-catenin activated (highest risk for malignant transformation) adenomas. Our patient had inflammatory and ß-catenin activation, which led to monitoring for malignant transformation. CONCLUSION: We report a ß-catenin activated inflammatory adenoma in a child with obesity and NASH with ongoing expectant management.

Argininosuccinate synthase 1 (ASS1): A marker of unclassified hepatocellular adenoma and high bleeding risk.

Hepatocellular adenomas (HCAs) are rare benign tumors divided into three main subgroups defined by pathomolecular features, HNF1A (H-HCA), mutated ß-catenin (b-HCA), and inflammatory (IHCA). In the case of unclassified HCAs (UHCAs), which are currently identified by default, a high risk of bleeding remains a clinical issue. The objective of this study was to explore UHCA proteome with the aim to identify specific biomarkers. Following dissection of the tumoral (T) and nontumoral (NT) tissue on formalin-fixed, paraffin-embedded HCA tissue sections using laser capture methodology, we performed mass spectrometry analysis to compare T and NT protein expression levels in H-HCA, IHCA, b-HCA, UHCA, and focal nodular hyperplasia. Using this methodology, we searched for proteins which are specifically deregulated in UHCA. We demonstrate that proteomic profiles allow for discriminating known HCA subtypes through identification of classical biomarkers in each HCA subgroup. We observed specific up-regulation of the arginine synthesis pathway associated with overexpression of argininosuccinate synthase (ASS1) and arginosuccinate lyase in UHCA. ASS1 immunohistochemistry identified all the UHCA, of which 64.7% presented clinical bleeding manifestations. Interestingly, we demonstrated that the significance of ASS1 was not restricted to UHCA, but also encompassed certain hemorrhagic cases in other HCA subtypes, particularly IHCA. CONCLUSION: ASS1 + HCA combined with a typical hematoxylin and eosin stain aspect defined a new HCA subgroup at a high risk of bleeding. (Hepatology 2017;66:2016-2028).

A Limited Immunohistochemical Panel Can Subtype Hepatocellular Adenomas for Routine Practice.

OBJECTIVES: ß-Catenin-activated hepatocellular adenomas have an elevated risk of harboring foci of hepatocellular carcinoma. Inflammatory adenomas also have an increased propensity for malignant transformation and are associated with a systemic inflammatory syndrome. Patients with these two adenoma subtypes benefit from excision. We assessed whether ß-catenin-activated and inflammatory adenomas could be identified using a limited immunohistochemical panel. METHODS: Forty-six adenomas were assessed by morphology and ß-catenin, serum amyloid A, and glutamine synthetase immunostains. RESULTS: Morphologic examination produced a morphologic working diagnosis of inflammatory adenoma in 25 (54%) of 46 cases, ß-catenin-activated adenoma in three (7%) of 46 cases, and 18 (39%) of 46 cases of other adenomas. After immunohistochemical staining, the morphologic diagnosis was confirmed in 15 (33%) of 46 and changed in 20 (43%) of 46, for a final distribution of 16 (35%) of 46 inflammatory adenomas, four (9%) of 46 ß-catenin-activated adenomas, seven (15%) of 46 ß-catenin-activated inflammatory adenomas, and 19 (41%) of 46 other adenomas. CONCLUSIONS: Inflammatory and ß-catenin-activated adenomas were readily identified by immunostaining patterns. These findings reinforce the necessity of immunohistochemistry in classifying adenomas, as assessing morphology alone often provided inaccurate subclassification. ß-Catenin-activated and inflammatory adenomas can be accurately diagnosed using only a limited panel of widely available immunostains.