Recent Advances in Pathology of Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICCA) is a malignant epithelial neoplasm characterized by biliary differentiation within the liver. ICCA is molecularly heterogeneous and exhibits a broad spectrum of histopathological features. It is a highly aggressive carcinoma with high mortality and poor survival rates. ICCAs are classified into two main subtypes: the small-duct type and large-duct types. These two tumor types have different cell origins and clinicopathological features. ICCAs are characterized by numerous molecular alterations, including mutations in KRAS, TP53, IDH1/2, ARID1A, BAP1, BRAF, SAMD4, and EGFR, and FGFR2 fusion. Two main molecular subtypes-inflammation and proliferation-have been proposed. Recent advances in high-throughput assays using next-generation sequencing have improved our understanding of ICCA pathogenesis and molecular genetics. The diagnosis of ICCA poses a significant challenge for pathologists because of its varied morphologies and phenotypes. Accurate diagnosis of ICCA is essential for effective patient management and prognostic determination. This article provides an updated overview of ICCA pathology, focusing particularly on molecular features, histological subtypes, and diagnostic approaches.

Macroscopic Characterization of Hepatocellular Carcinoma: An Underexploited Source of Prognostic Factors

The macroscopic appearance of a tumor such as hepatocellular carcinoma (HCC) may be defined as its phenotype which is de facto dictated by its genotype. Therefore, macroscopic characteristics of HCC are unlikely random but rather reflect genomic traits of cancer, presumably acting as a valuable source of information that can be retrieved and exploited to infer prognosis. This review aims to provide a comprehensive overview of the available data on the prognostic value of macroscopic characterization in HCC. A total of 57 studies meeting eligible criteria were identified, including patients undergoing liver resection (LR; 47 studies, 83%) or liver transplant (LT; 9 studies, 16%). The following macroscopic variables were investigated: tumor size (n = 42 studies), number of nodules (n = 28), vascular invasion (n = 24), bile duct invasion (n = 6), growth pattern (n = 15), resection margin (n = 11), tumor location (n = 6), capsule (n = 2) and satellite (n = 1). Although the selected studies provided insightful data with notable prognostic performances, a lack of standardization and substantial gaps were noted in the report and the analysis of gross findings. This topic remains incompletely covered. While the available studies underscored the value of macroscopic variables in HCC prognostication, important lacks were also observed. Macroscopic characterization of HCC is likely an underexploited source of prognostic factors that must be actively explored by future multidisciplinary research.

Advances in Histological and Molecular Classification of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a primary liver cancer characterized by hepatocellular differentiation. HCC is molecularly heterogeneous with a wide spectrum of histopathology. The prognosis of patients with HCC is generally poor, especially in those with advanced stages. HCC remains a diagnostic challenge for pathologists because of its morphological and phenotypic diversity. However, recent advances have enhanced our understanding of the molecular genetics and histological subtypes of HCC. Accurate diagnosis of HCC is important for patient management and prognosis. This review provides an update on HCC pathology, focusing on molecular genetics, histological subtypes, and diagnostic approaches.

Novel microenvironment-based classification of intrahepatic cholangiocarcinoma with therapeutic implications

OBJECTIVE

The diversity of the tumour microenvironment (TME) of intrahepatic cholangiocarcinoma (iCCA) has not been comprehensively assessed. We aimed to generate a novel molecular iCCA classifier that incorporates elements of the stroma, tumour and immune microenvironment ('STIM' classification).

DESIGN

We applied virtual deconvolution to transcriptomic data from ~900 iCCAs, enabling us to devise a novel classification by selecting for the most relevant TME components. Murine models were generated through hydrodynamic tail vein injection and compared with the human disease.

RESULTS

iCCA is composed of five robust STIM classes encompassing both inflamed (35%) and non-inflamed profiles (65%). The inflamed classes, named immune classical (~10%) and inflammatory stroma (~25%), differ in oncogenic pathways and extent of desmoplasia, with the inflammatory stroma showing T cell exhaustion, abundant stroma and KRAS mutations (p<0.001). Analysis of cell-cell interactions highlights cancer-associated fibroblast subtypes as potential mediators of immune evasion. Among the non-inflamed classes, the desert-like class (~20%) harbours the lowest immune infiltration with abundant regulatory T cells (p<0.001), whereas the hepatic stem-like class (~35%) is enriched in 'M2-like' macrophages, mutations in IDH1/2 and BAP1, and FGFR2 fusions. The remaining class (tumour classical: ~10%) is defined by cell cycle pathways and poor prognosis. Comparative analysis unveils high similarity between a KRAS/p19 murine model and the inflammatory stroma class (p=0.02). The KRAS-SOS inhibitor, BI3406, sensitises a KRAS-mutant iCCA murine model to anti-PD1 therapy.

CONCLUSIONS

We describe a comprehensive TME-based stratification of iCCA. Cross-species analysis establishes murine models that align closely to human iCCA for the preclinical testing of combination strategies.

Inflamed and non-inflamed classes of HCC: a revised immunogenomic classification

OBJECTIVE

We previously reported a characterisation of the hepatocellular carcinoma (HCC) immune contexture and described an immune-specific class. We now aim to further delineate the immunogenomic classification of HCC to incorporate features that explain responses/resistance to immunotherapy.

DESIGN

We performed RNA and whole-exome sequencing, T-cell receptor (TCR)-sequencing, multiplex immunofluorescence and immunohistochemistry in a novel cohort of 240 HCC patients and validated our results in other cohorts comprising 660 patients.

RESULTS

Our integrative analysis led to define: (1) the inflamed class of HCC (37%), which includes the previously reported immune subclass (22%) and a new immune-like subclass (15%) with high interferon signalling, cytolytic activity, expression of immune-effector cytokines and a more diverse T-cell repertoire. A 20-gene signature was able to capture ~90% of these tumours and is associated with response to immunotherapy. Proteins identified in liquid biopsies recapitulated the inflamed class with an area under the ROC curve (AUC) of 0.91; (2) The intermediate class, enriched in TP53 mutations (49% vs 29%, p=0.035), and chromosomal losses involving immune-related genes and; (3) the excluded class, enriched in CTNNB1 mutations (93% vs 27%, p<0.001) and PTK2 overexpression due to gene amplification and promoter hypomethylation. CTNNB1 mutations outside the excluded class led to weak activation of the Wnt-βcatenin pathway or occurred in HCCs dominated by high interferon signalling and type I antigen presenting genes.

CONCLUSION

We have characterised the immunogenomic contexture of HCC and defined inflamed and non-inflamed tumours. Two distinct CTNNB1 patterns associated with a differential role in immune evasion are described. These features may help predict immune response in HCC.

Whole Slide Imaging for Teleconsultation: The Mount Sinai Hospital, Labcorp Dianon, and Philips Collaborative Experience

Background:

With the emergence of whole slide imaging (WSI) and widespread access to high-speed Internet, pathology labs are now poised to implement digital pathology as a way to access diagnostic pathology expertise. This paper describes a collaborative partnership between a high-volume reference diagnostic laboratory (Labcorp) and an academic pathology department (Mount Sinai Hospital) in the transition from a traditional glass slide service to a digital platform. Using the standard framework of implementation science, we evaluate the consistency and quality of the Philips IntelliSite Pathology Solution (PIPS) in delivering save and efficient diagnostic services.

Materials and Methods:

Digital and glass slide diagnoses of all consult cases were documented over a 12-month period. The Proctor guideline was used to quantitatively and qualitatively measure (e.g., focus group studies, field notes, and administrative data) implementation success. Lean techniques (e.g., value stream mapping) were applied to measure changes in efficiency with the transition to a digital platform.

Results:

Our study supports the acceptability, high adoption, appropriateness, feasibility, fidelity, and sustainability of the digital pathology platform. The digital portal also improved the quality of patient care by increasing efficiency, effectiveness, safety, and timeliness. The intraobserver concordance rate was 100%. The digital transition resulted in a reduction in turnaround time from 86 h to an average 35 min and a 20-fold increase in efficiency of the consultation process.

Conclusion:

As the pathology community contemplates digital pathology as a transformational tool in providing broad access to diagnostic expertise across time and space, our study provides an implementation strategy along with evidence that the digital platform is safe, effective, and efficient.

Molecular characterisation of hepatocellular carcinoma in patients with non-alcoholic steatohepatitis

BACKGROUND AND AIMS

Non-alcoholic steatohepatitis (NASH)-related hepatocellular carcinoma (HCC) is increasing globally, but its molecular features are not well defined. We aimed to identify unique molecular traits characterising NASH-HCC compared to other HCC aetiologies.

METHODS

We collected 80 NASH-HCC and 125 NASH samples from 5 institutions. Expression array (n = 53 NASH-HCC; n = 74 NASH) and whole exome sequencing (n = 52 NASH-HCC) data were compared to HCCs of other aetiologies (n = 184). Three NASH-HCC mouse models were analysed by RNA-seq/expression-array (n = 20). Activin A receptor type 2A (ACVR2A) was silenced in HCC cells and proliferation assessed by colorimetric and colony formation assays.

RESULTS

Mutational profiling of NASH-HCC tumours revealed TERT promoter (56%), CTNNB1 (28%), TP53 (18%) and ACVR2A (10%) as the most frequently mutated genes. ACVR2A mutation rates were higher in NASH-HCC than in other HCC aetiologies (10% vs. 3%, p <0.05). In vitro, ACVR2A silencing prompted a significant increase in cell proliferation in HCC cells. We identified a novel mutational signature (MutSig-NASH-HCC) significantly associated with NASH-HCC (16% vs. 2% in viral/alcohol-HCC, p = 0.03). Tumour mutational burden was higher in non-cirrhotic than in cirrhotic NASH-HCCs (1.45 vs. 0.94 mutations/megabase; p <0.0017). Compared to other aetiologies of HCC, NASH-HCCs were enriched in bile and fatty acid signalling, oxidative stress and inflammation, and presented a higher fraction of Wnt/TGF-β proliferation subclass tumours (42% vs. 26%, p = 0.01) and a lower prevalence of the CTNNB1 subclass. Compared to other aetiologies, NASH-HCC showed a significantly higher prevalence of an immunosuppressive cancer field. In 3 murine models of NASH-HCC, key features of human NASH-HCC were preserved.

CONCLUSIONS

NASH-HCCs display unique molecular features including higher rates of ACVR2A mutations and the presence of a newly identified mutational signature.

LAY SUMMARY

The prevalence of hepatocellular carcinoma (HCC) associated with non-alcoholic steatohepatitis (NASH) is increasing globally, but its molecular traits are not well characterised. In this study, we uncovered higher rates of ACVR2A mutations (10%) - a potential tumour suppressor - and the presence of a novel mutational signature that characterises NASH-related HCC.

Findings of Hepatic Severe Acute Respiratory Syndrome Coronavirus-2 Infection

BACKGROUND & AIMS

Liver injury due to coronavirus disease 2019 (COVID-19) is being increasingly recognized. Abnormal liver chemistry tests of varying severities occur in a majority of patients. However, there is a dearth of accompanying liver histologic studies in these patients.

METHODS

The current report details the clinical courses of 2 patients having severe COVID-19 hepatitis. Liver biopsies were analyzed under light microscopy, portions of liver tissue were hybridized with a target probe to the severe acute respiratory syndrome coronavirus-2 S gene, and small sections from formalin-fixed paraffin-embedded liver tissue were processed for electron microscopy.

RESULTS

The liver histology of both cases showed a mixed inflammatory infiltrate with prominent bile duct damage, endotheliitis, and many apoptotic bodies. In situ hybridization and electron microscopy suggest the intrahepatic presence of severe acute respiratory syndrome coronavirus-2, the findings of which may indicate the possibility of direct cell injury.

CONCLUSIONS

On the basis of the abundant apoptosis and severe cholangiocyte injury, these histopathologic changes suggest a direct cytopathic injury. Furthermore, some of the histopathologic changes may resemble acute cellular rejection occurring after liver transplantation. These 2 cases demonstrate that severe COVID-19 hepatitis can occur even in the absence of significant involvement of other organs.

Aberrant von Willebrand factor expression of sinusoidal endothelial cells and quiescence of hepatic stellate cells in nodular regenerative hyperplasia and obliterative portal venopathy

AIMS

Nodular regenerative hyperplasia (NRH) and obliterative portal venopathy (OPV), entities that comprise idiopathic non-cirrhotic portal hypertension (INCPH), are under-recognised diseases of uncertain aetiology and the diagnosis can be easily missed on liver biopsy. The expression of CD34 and von Willebrand factor (vWF) in liver sinusoidal endothelial cells (LSEC) and alpha-smooth muscle actin (ASMA) in hepatic stellate cells (HSCs) is unknown in NRH and OPV. We sought to investigate the pathogenesis and potential immunomarkers that might aid in making the diagnosis of NRH and OPV.

METHODS AND RESULTS

Immunohistochemical (IHC) staining for CD34, vWF and ASMA was performed in clinically and histologically well-characterised NRH (n = 15) and OPV (n = 47) liver specimens. Among the 47 OPV cases, 37 (78.7%) had concurrent features of NRH. CD34 positive staining was mainly confined to small vessels in the portal tracts and LSECs in periportal areas, a finding similar to that in non-NRH/OPV livers. However, expression of vWF in LSECs was positive in the compressed sinusoids of NRH and in a patchy or geographic pattern, particularly prominent in the perivenular areas and dilated sinusoids of OPV cases. HSCs were negative for ASMA in all NRH and OPV cases.

CONCLUSION

Our findings indicate that NRH may be a subtle but common concurrent morphological feature in OPV. The aberrant expression of vWF in LSECs suggests that endothelial injury may play a role in the pathogenesis, which may thus aid in the recognition and diagnosis of NRH and OPV, particularly when confronted with otherwise apparent normal liver histology on needle biopsy.

Malignant transformation of liver fatty acid binding protein-deficient hepatocellular adenomas: histopathologic spectrum of a rare phenomenon

The molecular classification of hepatocellular adenomas highlights a distinctive genotype-phenotype correlation. Malignant transformation is an exceptionally rare complication of hepatocyte nuclear factor 1α (HNF1A)-inactivated hepatocellular adenomas. This subtype is characterized by loss of liver fatty acid binding protein immunoexpression. In this study, we characterized the histopathologic spectrum of 13 liver fatty acid binding protein-deficient hepatocellular adenoma cases showing malignant transformation from multiple centers. Clinicopathologic characteristics of these patients were evaluated. Stains for reticulin, liver fatty acid binding protein, beta-catenin and glutamine synthetase were applied to these lesions. Moreover, the findings were compared to patients with β-catenin mutated hepatocellular adenoma. Liver fatty acid binding protein-deficient hepatocellular adenomas with borderline features/carcinoma were seen predominantly in females (77%) with an average age of 46 ± 18 years and multiple lesions (77%; five patients with adenomatosis). Meanwhile, β-catenin mutated hepatocellular adenoma patients with malignant transformation were predominantly male (67%, p = 0.018) with single lesion (86%, p = 0.0009). The largest liver fatty acid binding protein-deficient hepatocellular adenoma nodule in each patient ranged from 4 to 15.5 cm. Loss of liver fatty acid binding protein by immunohistochemistry was noted in all adenoma and borderline/carcinoma components. Features of malignant transformation were pseudoglandular architecture (85%), cytologic atypia (85%), architectural atypia (100%) and lack of steatosis (100%). Other findings included myxoid change (39%), peliosis (46%) and sinusoidal dilatation (46%). Molecular studies confirmed somatic inactivation of HNF1A in 3 cases and absence of TERT promotor and exon 3 CTNNB1 mutations in five cases. To summarize, liver fatty acid binding protein-deficient hepatocellular adenoma with malignant transformation is most frequently seen in female patients with multiple lesions. Most of these lesions demonstrate pseudoglandular architecture, cytologic and architectural atypia, with lack of steatosis. The natural history of these lesions is relatively benign with the exception of disease recurrence in 1 patient.

Feasibility and safety of liver transplantation or resection after transarterial radioembolization with Yttrium-90 for unresectable hepatocellular carcinoma

BACKGROUND

The benefit of transarterial radioembolization (TARE) in patients with unresectable hepatocellular carcinoma (HCC) is increasingly evidenced. However, data on outcome of liver transplantation or resection after TARE remain scarce. This study aimed to assess the safety and feasibility of surgery after TARE in patients with unresectable HCC.

METHODS

Patients exclusively undergoing TARE followed by either orthotopic liver transplantation (OLT) or liver resection (LR) for HCC between 2012 and 2016 were included. Primary outcomes were postoperative morbidity and mortality. Secondary outcomes were overall survival (OS) and response to TARE.

RESULTS

Among 349 patients with HCC treated with TARE, 32 (9%) underwent either OLT (n = 22) or LR (n = 10), which represent the study cohort. In this group, TARE induced decreased viable nodules (p < 0.001), an efficient downsizing (p < 0.001) as well as a significant downstaging based on BCLC classification (p < 0.001). Overall, major complications and mortality after surgery occurred in 5 (16%) and 1 (3%) patients, respectively. For the whole study cohort, OS was 47 months while survival rates at 1-, 3- and 5-years reached 97%, 86% and 86%, respectively.

DISCUSSION

Liver surgery after TARE is feasible and safe. This strategy allows to offer a curative treatment in a subset of patients with unresectable HCC.

Frequent GNAQ and GNA14 Mutations in Hepatic Small Vessel Neoplasm

Hepatic small vessel neoplasm (HSVN) is a recently described infiltrative vascular neoplasm of the liver, composed of small vessels. Although the infiltrative nature can mimic angiosarcoma, HSVN are thought to be benign or low-grade neoplasms because they lack cytologic atypia and increased proliferation. To characterize the molecular pathogenesis of HSVN, we performed both targeted panel sequencing and exome sequencing on 18 benign or low-grade vascular neoplasms in the liver including 8 HSVN, 6 classic cavernous hemangioma (CH), and 4 variant lesions (VL) with overlapping features between HSVN and CH. All 18 lesions had simple genomes without copy number alterations. In total, 75% (6/8) of HSVN demonstrated known activating hotspot mutations in GNAQ (2/8, p.Q209H) or GNA14 (4/8, p.Q205L), and the remaining 2 had the same missense mutation in GNAQ, p.G48L, which has not been previously described. 25% (1/4) of VL had a hotspot GNAQ p.Q209H mutation and another VL had a GNAQ p.G48L mutation. Known pathogenic mutations were not identified in any of the 6 CH. These data suggest that HSVN share a similar molecular biology to several other vascular lesions (congenital hemangioma, tufted angioma, anastomosing hemangioma, lobular capillary hemangioma, and kaposiform hemangioendothelioma) recently reported to have GNAQ, GNA11, or GNA14 mutations.

Abstract 461: Distinctive molecular traits of hepatocellular carcinoma in patients with non-alcoholic steatohepatitis

Background and aim: Non-alcoholic steatohepatitis (NASH) is emerging as one of the leading risk factors for hepatocellular carcinoma (HCC), but its molecular pathogenesis is still ill-defined. This study aims to identify unique molecular traits that differentiate NASH-HCC from other aetiologies through an integrative molecular characterization.

Methods: A total of 225 tissue samples were collected, including samples from 125 biopsied/transplanted NASH patients; and 100 resected/transplanted NASH-HCC patients. Molecular characterization of FFPE samples, comprised expression array (n=53 NASH-HCC; n=74 NASH), whole exome sequencing (n=50 NASH-HCC), and SNP array (n=44 NASH-HCC). Publicly available data from HCV/HBV/alcohol-related HCCs were used to identify NASH-HCC distinctive traits.

Results: NASH-HCC patients compared to NASH non-HCC patients were prevalently males (82% vs 42%, p&lt;0.001), older (67 years vs 54, p&lt;0.01), with higher diabetes incidence (72% vs 50%, p=0.004), hypertension (80% vs 52%, p&lt;0.01) and cirrhosis (69% vs 29%, p&lt;0.001). Analysis of the transcriptome showed enrichment of liver metabolism pathways in NASH livers, whereas NASH-liver tissues of HCC cases were characterized by inflammation (TNFα-NFkβ, IL6, STAT3), epithelial-mesenchymal transition (TGFβ1), proliferation (AKT, mTOR), and poor-prognosis liver signatures (p&lt;0.05). Gene expression profiles of NASH-HCC tumours demonstrated that they can be classified in proliferation (50%) and non-proliferation (50%) molecular classes, as in non-NASH HCC. Mutational profiling of NASH-HCC tumours identified 4 genes with mutations in ≥10% of cases: TERT (52%), CTNNB1 (28%), TP53 (18%) and the TGFβ-receptor ACVR2A (10%). Interestingly, mutations in ACVR2A were three times more prevalent in NASH-HCC (n=100) than in viral/alcohol-related HCC (n=624)(2.6%, p&lt;0.05). Functional impact of ACVR2A mutations is currently being investigated. Finally, unsupervised clustering of mutational signatures showed that NASH-HCC tumours are clustered in 2 groups, enriched in liver-cancer signatures #16 (44%) and #5(22%), respectively; and that a third cluster (15%) was enriched in signature #3, which is novel in liver cancer. By comparing these results with the clustering of mutational profiles from viral/alcohol-related HCCs, we identified the signature#3-cluster as specific of NASH-HCC.

Conclusions: Non-tumour liver tissue of NASH-HCC patients is characterized by a cancer-field enriched in inflammatory, epithelial-to-mesenchymal transition and proliferation signalling pathways. NASH-HCC tumours showed a high frequency of ACVR2A mutations (10%), and a novel cancer mutational signature #3 (15%), suggesting genotoxic factors specifically associated to this entity.

Citation Format: Sara Torrecilla, Roser Pinyol, Huan Wang, Carla Montironi, Carmen Andreu-Oller, Wei Qiang Leow, Agrin Moeini, Claudia Oliveira, Venancio Avancini Ferreira Alves, Anja Lachenmayer, Stephanie Roessler, Beatriz Minguez, Peter Schirmacher, Paolo Boffetta, Jean-François Dufour, Swan N Thung, Andrew Uzilov, Flair Jose Carrilho, Charissa Chang, Daniela Sia, Josep M Llovet. Distinctive molecular traits of hepatocellular carcinoma in patients with non-alcoholic steatohepatitis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 461.

Molecular predictors of prevention of recurrence in HCC with sorafenib as adjuvant treatment and prognostic factors in the phase 3 STORM trial

OBJECTIVE

Sorafenib is the standard systemic therapy for advanced hepatocellular carcinoma (HCC). Survival benefits of resection/local ablation for early HCC are compromised by 70% 5-year recurrence rates. The phase 3 STORM trial comparing sorafenib with placebo as adjuvant treatment did not achieve its primary endpoint of improving recurrence-free survival (RFS). The biomarker companion study BIOSTORM aims to define (A) predictors of recurrence prevention with sorafenib and (B) prognostic factors with B level of evidence.

DESIGN

Tumour tissue from 188 patients randomised to receive sorafenib (83) or placebo (105) in the STORM trial was collected. Analyses included gene expression profiling, targeted exome sequencing (19 known oncodrivers), immunohistochemistry (pERK, pVEGFR2, Ki67), fluorescence in situ hybridisation (VEGFA) and immunome. A gene signature capturing improved RFS in sorafenib-treated patients was generated. All 70 RFS events were recurrences, thus time to recurrence equalled RFS. Predictive and prognostic value was assessed using Cox regression models and interaction test.

RESULTS

BIOSTORM recapitulates clinicopathological characteristics of STORM. None of the biomarkers tested (related to angiogenesis and proliferation) or previously proposed gene signatures, or mutations predicted sorafenib benefit or recurrence. A newly generated 146-gene signature identifying 30% of patients captured benefit to sorafenib in terms of RFS (p of interaction=0.04). These sorafenib RFS responders were significantly enriched in CD4+ T, B and cytolytic natural killer cells, and lacked activated adaptive immune components. Hepatocytic pERK (HR=2.41; p=0.012) and microvascular invasion (HR=2.09; p=0.017) were independent prognostic factors.

CONCLUSION

In BIOSTORM, only hepatocytic pERK and microvascular invasion predicted poor RFS. No mutation, gene amplification or previously proposed gene signatures predicted sorafenib benefit. A newly generated multigene signature associated with improved RFS on sorafenib warrants further validation.

TRIAL REGISTRATION NUMBER

NCT00692770.

A phenotypical map of disseminated hepatocellular carcinoma suggests clonal constraints in metastatic sites

AIMS

Access to tissue in patients with hepatocellular carcinoma (HCC) is limited compared to other malignancies, particularly at advanced stages. This has precluded a thorough characterisation of molecular drivers of HCC dissemination, particularly in relation to distant metastases. Biomarker assessment is restricted to early stages, and paired primary-metastatic comparisons between samples from the same patient are difficult.

METHODS AND RESULTS

We report the evaluation of 88 patients with HCC who underwent autopsy, including multiregional sampling of primary and metastatic sites totalling 230 nodules analysed. The study included morphological assessment, immunohistochemistry and mutation status of the TERT promoter, the most frequently mutated gene in HCC. We confirm a strong predilection of HCC for lung dissemination, including subclinical micrometastases (unrecognised during imaging and macroscopic examinations) in 30% of patients with disseminated disease. Size of dominant tumour nodule; multinodularity; macrovascular invasion; high histological, nuclear and architectural grades; and cellular crowding were associated with the presence of extrahepatic metastasis. Among the immunohistochemistry markers tested, metastatic nodules had significantly higher K19 and EpCAM expression than primary liver tumours. Morphological and immunohistochemical features showed that metastatic HCC could be traced back to the primary tumour, sometimes to a specific hepatic nodule.

CONCLUSIONS

This study suggests limited heterogeneity in metastatic sites compared to primary tumour sites.

A pilot study of ultra-deep targeted sequencing of plasma DNA identifies driver mutations in hepatocellular carcinoma

Cellular components of solid tumors including DNA are released into the bloodstream, but data on circulating-free DNA (cfDNA) in hepatocellular carcinoma (HCC) are still scarce. This study aimed at analyzing mutations in cfDNA and their correlation with tissue mutations in patients with HCC. We included 8 HCC patients treated with surgical resection for whom we collected paired tissue and plasma/serum samples. We analyzed 45 specimens, including multiregional tumor tissue sampling (n = 24), peripheral blood mononuclear cells (PMBC, n = 8), plasma (n = 8) and serum (n = 5). Ultra-deep sequencing (5500× coverage) of all exons was performed in a targeted panel of 58 genes, including frequent HCC driver genes and druggable mutations. Mutations detected in plasma included known HCC oncogenes and tumor suppressors (e.g., TERT promoter, TP53, and NTRK3) as well as a candidate druggable mutation (JAK1). This approach increased the detection rates previously reported for mutations in plasma of HCC patients. A thorough characterization of cis mutations found in plasma confirmed their tumoral origin, which provides definitive evidence of the release of HCC-derived DNA fragments into the bloodstream. This study demonstrates that ultra-deep sequencing of cfDNA is feasible and can confidently detect somatic mutations found in tissue; these data reinforce the role of plasma DNA as a promising minimally invasive tool to interrogate HCC genetics.

Acute-on-chronic liver failure 2018: a need for (urgent) liver biopsy?

'Acute-on-Chronic-Liver Failure (ACLF)' entered hepatology practice by the end of the 20th century. Although we lack precise and universally agreed definitions, acute decompensation of chronic liver disease with jaundice and deranged clotting, multi-organ failure and high, short-term mortality are hallmarks of the syndrome. Timely recognition and and treatment, including urgent liver transplantation, may save the life of certain patients. The diagnosis and management are mostly based on clinical features, but some have suggested to incorporate histopathology (liver biopsy). This may add to the differentiation between acute and chronic disease, primary and concomitant etiologies, and identify prognostic determinants. Areas covered: A review of the literature on ACLF and the outcome of the discussions at a topical international meeting on specific histopathological aspects of diagnosis and prognosis of the syndrome. Expert commentary: There is a lack of standardized descriptions of histopathological features and there is limited prospective experience with the role of pathology of ACLF. It is important for the clinical hepatologist to understand the potential and limitations of (transjugular) liver biopsy in ACLF and for the pathologist to help address the clinical question and recognise the histopathological features that help to characterize ACLF, both in terms of diagnosis and prognosis.

Chaperone-mediated autophagy compensates for impaired macroautophagy in the cirrhotic liver to promote hepatocellular carcinoma

Macroautophagy and chaperone-mediated autophagy (CMA) represent two major lysosomal degradation processes and often compensate for one another to facilitate cell survival. The aim of this study was to determine whether these autophagy pathways could compensate for one another to promote HCC cell survival in the cirrhotic liver. Analysis of normal liver tissue showed no expression of glypican-3 or p62 proteins, suggesting that macroautophagy is the major contributor to autophagic flux under non-pathological conditions. Of 46 cirrhotic livers with HCC examined, 39 (84%) of HCCs showed increased expression of p62, and 36 (78%) showed increased expression of glypican-3, while adjacent non-tumorous hepatocytes were negative for expression of p62 and glypican-3, similar to normal liver tissue. These results suggest that macroautophagy flux is impaired in HCC. Furthermore, more than 95% of HCCs showed altered expression of LAMP-2A compared to the surrounding non-tumorous cirrhotic liver, consistent with induction of CMA in HCC. Elevated expression of glucose-regulated protein 78 (GRP78) and heat shock cognate protein (Hsc70) were detected in 100% of HCC and adjacent non-tumorous cirrhotic livers, suggesting that unresolved ER-stress is associated with HCC risk in liver cirrhosis. Interestingly, inhibition of lysosomal degradation using hydroxychloroquine (HCQ) induced expression of the tumor suppressor p53, promoted apoptosis, and inhibited HCC growth, whereas activation of autophagy using an mTOR inhibitor (Torin1) promoted HCC growth. Results of this study suggest that induction of CMA compensates for the impairment of macroautophagy to promote HCC survival in the cirrhotic liver.

Combination of Gene Expression Signature and Model for End-Stage Liver Disease Score Predicts Survival of Patients With Severe Alcoholic Hepatitis

BACKGROUND & AIMS

Patients with severe alcoholic hepatitis (AH) have a high risk of death within 90 days. Corticosteroids, which can cause severe adverse events, are the only treatment that increases short-term survival. It is a challenge to predict outcomes of patients with severe AH. Therefore, we developed a scoring system to predict patient survival, integrating baseline molecular and clinical variables.

METHODS

We obtained fixed liver biopsy samples from 71 consecutive patients diagnosed with severe AH and treated with corticosteroids from July 2006 through December 2013 in Brussels, Belgium (derivation cohort). Gene expression patterns were analyzed by microarrays and clinical data were collected for 180 days. We identified gene expression signatures and clinical data that are associated with survival without liver transplantation at 90 and 180 days after initiation of corticosteroid therapy. Findings were validated using liver biopsies from 48 consecutive patients with severe AH treated with corticosteroids, collected from March 2010 through February 2015 at hospitals in Belgium and Switzerland (validation cohort 1) and in liver biopsies from 20 patients (9 received corticosteroid treatment), collected from January 2012 through May 2015 in the United States (validation cohort 2).

RESULTS

We integrated data on expression patterns of 123 genes and the model for end-stage liver disease (MELD) scores to assign patients to groups with poor survival (29% survived 90 days and 26% survived 180 days) and good survival (76% survived 90 days and 65% survived 180 days) (P < .001) in the derivation cohort. We named this assignment system the gene signature-MELD (gs-MELD) score. In validation cohort 1, the gs-MELD score discriminated patients with poor survival (43% survived 90 days) from those with good survival (96% survived 90 days) (P < .001). The gs-MELD score also discriminated between patients with a poor survival at 180 days (34% survived) and a good survival at 180 days (84% survived) (P < .001). The time-dependent area under the receiver operator characteristic curve for the score was 0.86 (95% confidence interval 0.73-0.99) for survival at 90 days, and 0.83 (95% confidence interval 0.71-0.96) for survival at 180 days. This score outperformed other clinical models to predict survival of patients with severe AH in validation cohort 1. In validation cohort 2, the gs-MELD discriminated patients with a poor survival at 90 days (12% survived) from those with a good survival at 90 days (100%) (P < .001).

CONCLUSIONS

We integrated data on baseline liver gene expression pattern and the MELD score to create the gs-MELD scoring system, which identifies patients with severe AH, treated or not with corticosteroids, most and least likely to survive for 90 and 180 days.

Hepatic adenomatosis in liver cirrhosis

Hepatocellular adenoma (HCA) is a benign liver tumor most frequently occurring in women using oral contraception. HCA develops in normal or nearly normal livers and is extremely rare in cirrhosis. The authors present magnetic resonance imaging and histopathologic findings in a 57-year-old man with liver cirrhosis and hepatic adenomatosis. As the differentiation between HCA and hepatocellular carcinoma (HCC) can be difficult with imaging, we would like to highlight the importance of ancillary findings such as the presence of iron on MRI, which can be observed in HCA.

Identification of an Immune-specific Class of Hepatocellular Carcinoma, Based on Molecular Features

BACKGROUND & AIMS

Agents that induce an immune response against tumors by altering T-cell regulation have increased survival times of patients with advanced-stage tumors, such as melanoma or lung cancer. We aimed to characterize molecular features of immune cells that infiltrate hepatocellular carcinomas (HCCs) to determine whether these types of agents might be effective against liver tumors.

METHODS

We analyzed HCC samples from 956 patients. We separated gene expression profiles from tumor, stromal, and immune cells using a non-negative matrix factorization algorithm. We then analyzed the gene expression pattern of inflammatory cells in HCC tumor samples. We correlated expression patterns with the presence of immune cell infiltrates and immune regulatory molecules, determined by pathology and immunohistochemical analyses, in a training set of 228 HCC samples. We validated the correlation in a validation set of 728 tumor samples. Using data from 190 tumors in the Cancer Genome Atlas, we correlated immune cell gene expression profiles with numbers of chromosomal aberrations (based on single-nucleotide polymorphism array) and mutations (exome sequence data).

RESULTS

We found approximately 25% of HCCs to have markers of an inflammatory response, with high expression levels of the CD274 molecule (programmed death-ligand 1) and programmed cell death 1, markers of cytolytic activity, and fewer chromosomal aberrations. We called this group of tumors the Immune class. It contained 2 subtypes, characterized by markers of an adaptive T-cell response or exhausted immune response. The exhausted immune response subclass expressed many genes regulated by transforming growth factor beta 1 that mediate immunosuppression. We did not observe any differences in numbers of mutations or expression of tumor antigens between the immune-specific class and other HCCs.

CONCLUSIONS

In an analysis of HCC samples from 956 patients, we found almost 25% to express markers of an inflammatory response. We identified 2 subclasses, characterized by adaptive or exhausted immune responses. These findings indicate that some HCCs might be susceptible to therapeutic agents designed to block the regulatory pathways in T cells, such as programmed death-ligand 1, programmed cell death 1, or transforming growth factor beta 1 inhibitors.

Mixed hepatocellular cholangiocarcinoma tumors: Cholangiolocellular carcinoma is a distinct molecular entity

BACKGROUND & AIMS

Mixed hepatocellular cholangiocarcinoma (HCC-CCA) is a rare and poorly understood type of primary liver cancer. We aimed to perform a comprehensive molecular characterization of this malignancy.

METHODS

Gene expression profiling, DNA copy number detection, and exome sequencing using formalin-fixed samples from 18 patients with mixed HCC-CCA were performed, encompassing the whole histological spectrum of the disease. Comparative genomic analysis was carried out, using independent datasets of HCC (n=164) and intrahepatic cholangiocarcinoma (iCCA) (n=149).

RESULTS

Integrative genomic analysis of HCC-CCAs revealed that cholangiolocellular carcinoma (CLC) represents a distinct biliary-derived entity compared with the stem-cell and classical types. CLC tumors were neural cell adhesion molecule (NCAM) positive (6/6 vs. 1/12, p<0.001), chromosomally stable (mean chromosomal aberrations 5.7 vs. 14.1, p=0.008), showed significant upregulation of transforming growth factor (TGF)-β signaling and enrichment of inflammation-related and immune response signatures (p<0.001). Stem-cell tumors were characterized by spalt-like transcription factor 4 (SALL4) positivity (6/8 vs. 0/10, p<0.001), enrichment of progenitor-like signatures, activation of specific oncogenic pathways (i.e., MYC and insulin-like growth factor [IGF]), and signatures related to poor clinical outcome. In the classical type, there was a significant correlation in the copy number variation of the iCCA and HCC components, suggesting a clonal origin. Exome sequencing revealed an average of 63 non-synonymous mutations per tumor (2 mean driver mutations per tumor). Among those, TP53 was the most frequently mutated gene (6/21, 29%) in HCC-CCAs.

CONCLUSIONS

Mixed HCC-CCA represents a heterogeneous group of tumors, with the stem-cell type characterized by features of poor prognosis, and the classical type with common lineage for HCC and iCCA components. CLC stands alone as a distinct biliary-derived entity associated with chromosomal stability and active TGF-β signaling.

LAY SUMMARY

Molecular analysis of mixed hepatocellular cholangiocarcinoma (HCC-CCA) showed that cholangiolocellular carcinoma (CLC) is distinct and biliary in origin. It has none of the traits of hepatocellular carcinoma (HCC). However, within mixed HCC-CCA, stem-cell type tumors shared an aggressive nature and poor outcome, whereas the classic type showed a common cell lineage for both the HCC and the intrahepatic CCA component. The pathological classification of mixed HCC-CCA should be redefined because of the new molecular data provided.

Multifocal Intrahepatic Artery Aneurysm with FDG-avid Thrombosis Simulating Metastasis: Report of a Rare Case

Hepatic artery aneurysm (HAA), although rare, represents a serious diagnostic and therapeutic challenge due to high rupture rate and associated mortality. Early detection and accurate diagnosis are essential for successful management. Here, we present an extremely rare case of multi-focal intrahepatic HAA with confined intrahepatic rupture and hypermetabolic activity at PET imaging, simulating metastasis of melanoma. A retrospective review found only two other HAA at our institution between 2000 and 2015, both of which involved the extrahepatic artery. This report highlights the importance of clinical, radiological, and pathological correlation in the management of this rare condition.

2016 Comprehensive Update of the Banff Working Group on Liver Allograft Pathology: Introduction of Antibody-Mediated Rejection

The Banff Working Group on Liver Allograft Pathology reviewed and discussed literature evidence regarding antibody-mediated liver allograft rejection at the 11th (Paris, France, June 5-10, 2011), 12th (Comandatuba, Brazil, August 19-23, 2013), and 13th (Vancouver, British Columbia, Canada, October 5-10, 2015) meetings of the Banff Conference on Allograft Pathology. Discussion continued online. The primary goal was to introduce guidelines and consensus criteria for the diagnosis of liver allograft antibody-mediated rejection and provide a comprehensive update of all Banff Schema recommendations. Included are new recommendations for complement component 4d tissue staining and interpretation, staging liver allograft fibrosis, and findings related to immunosuppression minimization. In an effort to create a single reference document, previous unchanged criteria are also included.

Synchronous pancreatic adenocarcinoma and intrahepatic cholangiocarcinoma arising in the context of intraductal papillary neoplasms

Field cancerization theory provides rationale for the development of multiple pancreatic ductal and biliary lesions in a single patient through the development and accumulation of multiple genetic changes. Genetic alterations result in the development of precursor lesions including intraductal papillary mucinous neoplasms of the pancreas (IPMN), intraductal papillary neoplasm of the bile duct (IPN-B), and their malignant counterparts, pancreatic adenocarcinoma and cholangiocarcinoma. Although IPMN are frequently encountered, IPN-B are uncommon and the synchronous occurrence of both lesions is rare. We present a case of synchronous pancreatic adenocarcinoma and intrahepatic cholangiocarcinoma with histopathologic evidence of underlying precursor lesions, IPMN-P and IPN-B.

Hepatic small vessel neoplasm, a rare infiltrative vascular neoplasm of uncertain malignant potential

Characteristic but rare vascular neoplasms in the adult liver composed of small vessels with an infiltrative border were collected from an international group of collaborators over a 5-year period (N=17). These tumors were termed hepatic small vessel neoplasm (HSVN), and the histologic differential diagnosis was angiosarcoma (AS). The average age of patients was 54years (range, 24-83years). HSVN was more common in men. The average size was 2.1cm (range, 0.2-5.5cm). Diagnosis was aided by immunohistochemical stains for vascular lineage (CD31, CD34, FLI-1), which were uniformly positive in HSVN. Immunohistochemical stains (p53, c-Myc, GLUT-1, and Ki-67) for possible malignant potential are suggestive of a benign/low-grade tumor. Capture-based next-generation sequencing (using an assay that targets the coding regions of more than 500 cancer genes) identified an activating hotspot GNAQ mutation in 2 of 3 (67%) tested samples, and one of these cases also had a hotspot mutation in PIK3CA. When compared with hepatic AS (n=10) and cavernous hemangioma (n=6), the Ki-67 proliferative index is the most helpful tool in excluding AS, which demonstrated a tumor cell proliferative index greater than 10% in all cases. Strong p53 and diffuse c-Myc staining was also significantly associated with AS but not with HSVN or cavernous hemangioma. There have been no cases with rupture/hemorrhage, disseminated intravascular coagulation, or Kasabach-Merritt syndrome. Thus far, there has been no metastasis or recurrence of HSVN, but complete resection and close clinical follow-up are recommended because the outcome remains unknown.

An Unusual Cause of Acute Liver Failure: Three Cases of Hemophagocytic Lymphohistiocytosis Presenting at a Transplant Center

Acquired hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening disorder of the immune system. Hemophagocytic lymphohistiocytosis has been associated with infections, autoimmune disorders, and malignancy. This case series describes three patients admitted to an academic liver transplant center from February 2014 to February 2015 with acute liver failure (ALF) who were ultimately diagnosed with HLH. All cases were female patients (44 to 53 years of age) transferred for workup of ALF. All developed fevers and cytopenias and underwent rapid evaluation for liver transplant by a multidisciplinary team. A complete workup for ALF was negative for intrinsic liver disease and none had significant alcohol or toxin exposure. The patients had liver biopsies showing diffuse lobular necroinflammation, of which two had evidence of hemophagocytosis on histopathology. The diagnosis of HLH was made by bone marrow biopsy featuring histiocytes with hemophagocytosis. All cases were treated with chemotherapy, but died during their hospitalization. Hemophagocytic lymphohistiocytosis can present as ALF in adult patients. Given the low success rate of treatment, early diagnosis is critical. Therefore, a high degree of suspicion should be exercised in patients with unexplained ALF.

Liver pathology of hepatitis C, beyond grading and staging of the disease

Liver biopsy evaluation plays a critical role in management of patients with viral hepatitis C. In patients with acute viral hepatitis, a liver biopsy, though uncommonly performed, helps to rule out other non-viral causes of deranged liver function. In chronic viral hepatitis C, it is considered the gold standard in assessment of the degree of necroinflammation and the stage of fibrosis, to help guide treatment and determine prognosis. It also helps rule out any concomitant diseases such as steatohepatitis, hemochromatosis or others. In patients with chronic progressive liver disease with cirrhosis and dominant nodules, a targeted liver biopsy is helpful in differentiating a regenerative nodule from dysplastic nodule or hepatocellular carcinoma. In the setting of transplantation, the liver biopsy helps distinguish recurrent hepatitis C from acute rejection and also is invaluable in the diagnosis of fibrosing cholestatic hepatitis, a rare variant of recurrent hepatitis C. This comprehensive review discusses the entire spectrum of pathologic findings in the course of hepatitis C infection.

Progenitor cell markers predict outcome of patients with hepatocellular carcinoma beyond Milan criteria undergoing liver transplantation

BACKGROUND & AIMS

In patients with hepatocellular carcinoma (HCC), liver transplantation (LT) is an excellent therapy if tumor characteristics are within the Milan criteria. We aimed to define genomic features enabling to identify HCC patients beyond Milan criteria who have acceptable transplant outcomes.

METHODS

Among 770 consecutive HCC patients transplanted between 1990 and 2013, 132 had tumors exceeding Milan criteria on pathology and were enrolled in the study; 44% of the patients satisfied the 'up-to-7 rule' [7=sum of the size of the largest tumor and the number of tumors]. Explant tumors were assessed for genomic signatures and immunohistochemical markers associated with poor outcome.

RESULTS

At a median follow-up of 88months, 64 patients had died and 45 recurred; the 5-year overall survival (OS) and recurrence rates were 57% and 35%, respectively. Cytokeratin 19 (CK19) gene signature was independently associated with recurrence [Hazard ratio (HR)=2.95, p<0.001], along with tumor size (HR=3.37, p=0.023) and presence of satellites (HR=2.98, p=0.001). S2 subclass signature was independently associated with poor OS (HR=3.18, p=0.001), along with tumor size (HR=5.06, p<0.001) and up-to-7 rule (HR=2.50, p=0.002). Using the presence of progenitor cell markers (either CK19 or S2 signatures) patients were classified into poor prognosis (n=58; 5-year recurrence 53%, survival 45%) and good prognosis (n=74; 5-year recurrence 19%, survival 67%) (HR=3.16, p<0.001 for recurrence, and HR=1.72, p=0.04 for OS).

CONCLUSIONS

HCC patients transplanted beyond Milan criteria without gene signatures of progenitor markers (CK19 and S2) achieved survival rates similar as those within Milan criteria. Once prospectively validated, these markers may support a limited expansion of LT indications.

Hepatocellular Carcinoma Arising in an HNF-1α-Mutated Adenoma in a 23-Year-Old Woman with Maturity-Onset Diabetes of the Young: A Case Report

Hepatocyte nuclear factor-1α mutated hepatocellular adenomas (H-HCA) are thought to have no to minimal malignant potential. This report describes a 23-year-old woman with maturity-onset diabetes of the young who developed a 12.5-cm hepatic mass with a radiographically and pathologically distinct 3.0-cm region. Histologically and immunohistochemically, the bulk of the mass was an H-HCA with extensive pseudoglandular formation and only focal steatosis. The 3.0-cm nodule showed small cell change, thickened hepatocyte plates, pleomorphic and hyperchromatic nuclei, reticulin loss, and stromal and vascular invasion, diagnostic of hepatocellular carcinoma (HCC). Immunohistochemically, increased expression of glutamine synthetase in tumor cells and CD34 expression in sinusoidal endothelial cells were seen in the HCC component. Nuclear expression of β-catenin, and exon 3 of CTNNB1 and TERT promoter mutations were absent in this case. Thus, we report a HCC arising in an H-HCA; although cases appear exceedingly rare, they reinforce the potential of H-HCA for malignant transformation.

Outcomes following resection of intrahepatic cholangiocarcinoma

OBJECTIVES

The aim of this analysis was to examine prognostic features and outcomes in patients undergoing resection for intrahepatic cholangiocarcinoma (ICC).

METHODS

A retrospective chart review was performed in all patients who underwent R0 or R1 resection for primary ICC between 1995 and 2011. Clinical data were abstracted and statistical analyses were conducted in the standard fashion.

RESULTS

A total of 82 patients underwent curative hepatectomy for primary ICC; 51 patients in this cohort developed recurrence. The median follow-up of survivors was 27 months (range: 1-116 months). Recurrences were intrahepatic (65%), associated with multiple tumours (54%) and occurred during the first 2 years after hepatectomy (86%). The main factor associated with recurrence after resection was the presence of satellite lesions. Overall 5-year disease-free survival after primary resection was 16%. Factors associated with poor survival were transfusion and perineural invasion. Treatment of recurrence was undertaken in 89% of patients and repeat surgical resection was performed in 15 patients. The 3-year survival rate after recurrence was 25%. Prolonged survival after recurrence was associated with a solitary tumour recurrence.

CONCLUSIONS

Despite curative resection of ICC, recurrence can be expected to occur in 79% of patients at 5 years. Predictors of survival and recurrence after resection vary in the literature. In patients with recurrence, selection of the optimal treatment remains challenging.

Primary sclerosing cholangitis: detailed histologic assessment and integration using bioinformatics highlights arterial fibrointimal hyperplasia as a novel feature

OBJECTIVES

Liver biopsy diagnosis of primary sclerosing cholangitis (PSC) is difficult. We performed a detailed histologic analysis of PSC cases using novel bioinformatics analysis to identify histologic features that may be useful in its diagnosis.

METHODS

PSC liver explants were examined and compared with primary biliary cirrhosis and hepatitis C explants to act as controls. Demographic, macroscopic, and histologic variables were analyzed using both conventional statistics and an integrative bioinformatics approach, significance analysis of microarrays (SAM), and hierarchical clustering analysis (HCA).

RESULTS

The PSC group was younger and had distinctive PSC features, including bile duct scars, onion-skin fibrosis, and arterial fibrointimal hyperplasia. SAM allowed the integration of variables by comparing PSC and control groups, whereas HCA was able to correctly categorize each group.

CONCLUSIONS

This study demonstrates characteristic PSC histology as well as arterial hyperplasia to be distinctive features that may aid in PSC diagnosis and be confirmed by bioinformatics.

Magnetic resonance imaging of a small vessel hepatic hemangioma in a cirrhotic patient with histopathologic correlation

The authors report and discuss a rare case of a small vessel hepatic hemangioma in a 59-year-old patient with liver cirrhosis, which was pre-procedurally characterized as indeterminate due to atypical magnetic resonance imaging (MRI) features. This manuscript reviews the MRI features with pathologic correlation, emphasizes the importance of accurate characterization of liver lesions, and discusses the role of biopsy. We believe this is the first reported case of a small vessel hemangioma in liver cirrhosis with imaging and histopathologic correlation.

Severe ductopenia and cholestasis from levofloxacin drug-induced liver injury: a case report and review

A 67-year-old woman with hypertension, hypothyroidism, and glaucoma was referred for jaundice and elevated liver function tests. She was treated for streptococcal endophthalmitis with 2 weeks of intravenous (IV) levofloxacin followed by 2 months of oral levofloxacin. The patient had no prior history of liver disease and denied alcohol intake. Her physical exam was remarkable for jaundice and scleral icterus without any stigmata of liver disease. Viral hepatitis serologies and antibodies, including myeloperoxidase, proteinase 3, and antinuclear, antimitochondrial, antiliver kidney microsome, antismooth muscle antibodies, were all within normal limits. The liver biopsy revealed severe cholestasis, extensive bile duct loss, and fibrosis. The patient had no known exposure to any other systemic medications or inciting factors other than levofloxacin. Although there are a few reported cases of drug-induced liver disease (DILI) related to levofloxacin, this case is believed to be the first reported case of ductopenia or vanishing bile duct syndrome (VBDS) associated with levofloxacin. Although fluoroquinolones, such as levofloxacin, are generally considered safe antibiotics, health practitioners must be aware of their association with DILI, as the diagnosis of DILI is one of exclusion and requires a high index of suspicion.

Case report of successful treatment of fibrosing cholestatic hepatitis C with sofosbuvir and ribavirin after liver transplantation

Fibrosing cholestatic hepatitis is an unusual complication of hepatitis C virus (HCV) recurrence after liver transplant. Fibrosing cholestatic hepatitis is marked by aggressive progression of cholestasis and fibrosis, leading to accelerated graft loss and/or death. Sofosbuvir (GS-7977) is an oral nucleotide analogue inhibitor of HCV polymerase activity. It is a second-generation, direct-acting, antiviral for the treatment of HCV infection. This case illustrates a patient with recurrent HCV with fibrosing cholestatic hepatitis, who was successfully treated with a combination of sofosbuvir and ribavirin with normalization of liver enzyme activities and resolution of HCV-related symptoms. The favorable side effect profile and the lack of drug-drug interaction with immunosuppressive medications make the combination of sofosbuvir and ribavirin a promising regimen for severe HCV recurrence.

Impaired autophagy response in human hepatocellular carcinoma

BACKGROUND

Autophagy is a cellular lysosomal degradation mechanism that has been implicated in chronic liver diseases and hepatocellular carcinoma (HCC). Association of autophagy defect with the development of human HCC has been shown in transgenic mouse model.

AIM

We performed this study to verify whether a defect in autophagy would play a role in human hepatocellular carcinoma (HCC).

METHODS

Archival tissue sections of 20 patients with HCC with or without hepatitis C virus (HCV) infection were studied. All slides were immunostained using monoclonal antibodies to p62 and glypican-3 with appropriate positive and negative controls. The expression of p62 and glycican-3 in the HCC and the surrounding non-tumor was semiquantitated. The cytoplasmic staining was graded as negative, weak or strong.

RESULTS

Positive p62 staining was found in 20 out of 20 (100%) HCCs and negative staining was observed in 20 out of 20 non-tumor areas and cirrhotic nodules. Positive glypican-3 staining was found in 70% of HCCs and negative staining was seen in all non-tumor areas. An autophagy defect leading to increased expression of p62 and glypican-3 was also seen in the HCC cell line (Huh-7.5), but not in the primary human hepatocytes. Activation of cellular autophagy in Huh-7.5 cells efficiently cleared p62 and glypican-3 expression and inhibition of autophagy induced the expression of p62 and glypican-3.

CONCLUSIONS

This study shows that p62 is increased in HCC compared to the surrounding non-tumorous liver tissue suggesting that human HCCs are autophagy defective. We provide further evidence that glypican-3 expression in HCC may also be related to defective autophagy. Our study indicates that p62 immunostain may represent a novel marker for HCC.

Steatohepatitis secondary to long-term glucocorticoid treatment for congenital adrenal hyperplasia: a potential diagnostic pitfall

A 24-year-old woman with congenital adrenal hyperplasia (CAH) was referred for evaluation of elevated liver enzyme activities over the preceding 6 months. The patient was diagnosed with CAH at the age 12 when she presented with irregular menses and hirsutism. Since then, she had been on dexamethasone to maintain a normal menstrual cycle and prevent hirsutism and acne. She had no history of chronic liver disease and drank alcohol socially. An extensive workup for other treatable causes of liver disease was unrevealing. Therefore, a liver biopsy was performed, which revealed extensive ballooned degenerative hepatocytes containing Mallory-Denk hyalines. The ballooned hepatocytes were located predominantly in centrilobular areas and without any accompanying steatosis. Even though the histopathologic features are most compatible with alcoholic and/or nonalcoholic steatohepatitis, it was not supported by the patient's medical history and clinical presentation. The patient had a normal body mass index and only occasional alcohol use. Based on the biopsy finding and clinical presentation, we postulated that the abnormal liver enzyme and pathological features seen on the liver biopsy were secondary to CAH and long-term use of glucocorticoid. A few studies have shown that patients with CAH often develop metabolic abnormalities and insulin resistance, particularly women treated with glucocorticoid for several years. To our knowledge, this is the first report describing steatohepatitis secondary to CAH and prolonged glucocorticoid treatment. It is important to be aware that steatohepatitis can develop in these patients due to long-term glucocorticoid use and potentially lead to progressive liver damage. Furthermore, in patients with CAH who develop abnormal liver enzyme activities a liver biopsy is warranted to assess for steatohepatitis and any associated fibrosis. If indeed fibrosis is already present, a consultation with the endocrinologist should be undertaken in an effort to lower the dose of the glucocorticoids as much as possible while still controlling the symptoms of the disease.

Histopathologic manifestations of drug-induced hepatotoxicity

Drug-induced hepatotoxicity is underrecognized but increasingly identified as causing acute and chronic liver disease. Several prescription drugs, over-the-counter medications, dietary and/or supplementary agents, and herbal products are hepatotoxic. Drug-induced liver injury mimics other primary acute and chronic liver diseases and it should be considered in patients with hepatobiliary disease. Certain drugs result in specific histopathologic patterns of liver injury, which may help in sorting out the responsible drug. The diagnosis of drug-induced hepatotoxicity is challenging. It involves excluding other possible causes, careful medication history, the latent period between drug exposure and symptom onset and/or abnormal liver tests, and histopathologic findings.

A two-step right hepatic lobectomy with portal vein ligation for large hepatocellular carcinoma: rapid induction of left-lobe regeneration and clinicopathologic correlation

The patient is a 56-year-old man with a long history of chronic hepatitis B, who developed multiple hepatocellular carcinomas in the right lobe with invasion of the right anterior portal vein. There was no evidence of tumor involvement in the left lobe or in extrahepatic organs. Given that the patient had advanced hepatocellular carcinoma associated with gross vascular invasion, a two-step liver resection procedure was performed with right portal vein ligation during the first operation and a subsequent right lobectomy of the liver. The stage I portal vein ligation induced a rapid growth of the left and caudate lobes of the liver with a volume increase from 201 to 405.2 mL in 9 days associated with a slight shrinkage of the tumor nodules. The subsequent right lobectomy was successfully done with a complete removal of tumor nodules and a well-compensated liver function. Postoperatively the patient was complicated with Staphylococcus aureus peritonitis, which was controlled eventually. Biopsy of the left lobe of liver revealed severe small- and medium- droplet steatosis, in addition to regenerative changes. In summary, right portal vein ligation with in situ splitting of the liver allows the surgeon to proceed with hepatic resection in cases where portal vein embolization is technically not possible. The increased risk of morbidity and mortality certainly must be weighed when contemplating this approach and is discussed in this report.

Telangiectatic hyperplastic nodule associated with vascular malformation in a patient with chronic hepatitis B: radiologic and pathologic features

Recognizing hepatocellular nodules that cannot be classified as typical for hepatocellular carcinoma, hepatocellular adenoma, or focal nodular hyperplasia is important, especially in a patient with high risk for hepatocellular carcinoma. The authors report a case of a 53-year-old man with chronic hepatitis B, who was referred to the hospital with a liver mass found on routine imaging follow-up. Abdominal ultrasound revealed a 2.4-cm hypoechoic lesion. Contrast computed tomography showed homogeneous arterial enhancement and mild hyperdensity on portal venous phase images. Due to the high risk for hepatocellular carcinoma, the patient underwent laparoscopic left lateral segmentectomy that revealed a 2.2-cm poorly defined red-brown lesion. The nodule was diagnosed as a hypervascular/telangiectatic hyperplastic hepatocellular nodule based on histopathologic findings and immunostaining profile with negative glutamine synthetase, diffuse positive CD34 highlighting hyperplastic endothelial cells along the telangiectatic sinusoids and dilated vascular channels, and CK7 and CK19 reactive normal bile ducts within the lesion.

Focal Nodular Hyperplasia and Hepatocellular Adenoma around the World Viewed through the Scope of the Immunopathological Classification

Focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) are benign hepatocellular tumors. The risk of bleeding and malignant transformation of HCA are strong arguments to differentiate HCA from FNH. Despite great progress that has been made in the differential radiological diagnosis of the 2 types of nodules, liver biopsy is sometimes necessary to separate the 2 entities. Identification of HCA subtypes using immunohistochemical techniques, namely, HNF1A-inactivated HCA (35-40%), inflammatory HCA (IHCA), and beta-catenin-mutated inflammatory HCA (b-IHCA) (50-55%), beta-catenin-activated HCA (5-10%), and unclassified HCA (10%) has greatly improved the diagnostic accuracy of benign hepatocellular nodules. If HCA malignant transformation occurs in all HCA subgroups, the risk is by far the highest in the β -catenin-mutated subgroups (b-HCA, b-IHCA). In the coming decade the management of HCA will be more dependent on the identification of HCA subtypes, particularly for smaller nodules (<5 cm) in terms of imaging, follow-up, and resection.

Robust cellular reprogramming occurs spontaneously during liver regeneration

Cellular reprogramming-the ability to interconvert distinct cell types with defined factors-is transforming the field of regenerative medicine. However, this phenomenon has rarely been observed in vivo without exogenous factors. Here, we report that activation of Notch, a signaling pathway that mediates lineage segregation during liver development, is sufficient to reprogram hepatocytes into biliary epithelial cells (BECs). Moreover, using lineage tracing, we show that hepatocytes undergo widespread hepatocyte-to-BEC reprogramming following injuries that provoke a biliary response, a process requiring Notch. These results provide direct evidence that mammalian regeneration prompts extensive and dramatic changes in cellular identity under injury conditions.