Mechanisms of Sorafenib Resistance in HCC Culture Relate to the Impaired Membrane Expression of Organic Cation Transporter 1 (OCT1).

Introduction: Sorafenib, an FDA-approved drug for advanced hepatocellular carcinoma (HCC) treatment, encounters resistance in many patients. Deciphering the mechanisms underlying sorafenib resistance is crucial for devising alternative strategies to overcome it. Aim: This study aimed to investigate sorafenib resistance mechanisms using a diverse panel of HCC cell lines. Methods: HCC cell lines were subjected to continuous sorafenib treatment, and stable cell lines (Huh 7.5 and Huh 7PX) exhibiting sustained growth in its presence were isolated. The investigation of drug resistance mechanisms involved a comparative analysis of drug-targeted signal transduction pathways (EGFR/RAF/MEK/ERK/Cyclin D), sorafenib uptake, and membrane expression of the drug uptake transporter. Results: HCC cell lines (Huh 7.5 and Huh 7PX) with a higher IC50 (10µM) displayed a more frequent development of sorafenib resistance compared to those with a lower IC50 (2-4.8µM), indicating a potential impact of IC50 variation on initial treatment response. Our findings reveal that activated overexpression of Raf1 kinases and impaired sorafenib uptake, mediated by reduced membrane expression of organic cation transporter-1 (OCT1), contribute to sorafenib resistance in HCC cultures. Stable expression of the drug transporter OCT1 through cDNA transfection or adenoviral delivery of OCT1 mRNA increased sorafenib uptake and successfully overcame sorafenib resistance. Additionally, consistent with sorafenib resistance in HCC cultures, cirrhotic liver-associated human HCC tumors often exhibited impaired membrane expression of OCT1 and OCT3. Conclusion: Intrinsic differences among HCC cell clones, affecting sorafenib sensitivity at the expression level of Raf kinases, drug uptake, and OCT1 transporters, were identified. This study underscores the potential of HCC tumor targeted OCT1 expression to enhance sorafenib treatment response.

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.

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-ß 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.

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.

Morphology of tumor and nontumor tissue in liver resection specimens for hepatocellular carcinoma following nivolumab therapy.

Nivolumab is an immune checkpoint inhibitor (ICI) approved for treatment of many cancers, including hepatocellular carcinoma (HCC). Liver injury is a known complication in patients treated with nivolumab for nonliver tumors. To date, the morphologic changes to tumor and nontumor liver have not been well-characterized in HCC patients. We identified 20 patients who underwent partial hepatectomy or liver transplantation after receiving nivolumab for HCC. Demographics, laboratory values, and imaging results were obtained from medical records. All available slides from resection specimens were evaluated for tumor necrosis, tumor-infiltrating lymphocytes (TILs), and features of liver injury. Patients in the study included 16 males and 4 females with median age of 56 years. The underlying liver disease was HBV in 10, HCV in 6, and unknown/other in 4. Twelve patients were treated with nivolumab in the neoadjuvant setting, whereas eight were treated with nivolumab, usually along with other therapies, before undergoing liver transplantation. On review of resection specimens, three patients (all from the neoadjuvant group) demonstrated marked treatment response attributable to nivolumab. TILs were present in 17/20 cases. One case that showed treatment response in the neoadjuvant group demonstrated non-necrotizing granulomas and prominent bile duct intraepithelial lymphocytes (IELs) in the nontumor liver. One case from the transplant group showed bile duct damage and prominent ductular reaction after long-term nivolumab therapy (32 doses). Our findings indicate that nivolumab is effective in a subset of patients, including in the neoadjuvant setting. Granulomas and bile duct IELs are rare findings in cases treated with nivolumab but, when seen, may indicate potential response to therapy. Bile duct damage and ductular reaction may be manifestations of long-term nivolumab therapy. Future prospective and longitudinal studies with pretreatment tumor biopsies may help identify patients apt to respond to ICI therapy and further characterize patterns of ICI-related liver injury.

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.

Steatohepatitic Variant of Hepatocellular Carcinoma Is Associated With Both Alcoholic Steatohepatitis and Nonalcoholic Steatohepatitis: A Study of 2 Cohorts With Molecular Insights.

Steatohepatitic hepatocellular carcinoma (SH-HCC) is a variant of hepatocellular carcinoma (HCC) with established association with nonalcoholic steatohepatitis (NASH), while its association with alcoholic steatohepatitis (ASH) is unclear. We studied 2 cohorts of patients who underwent resection for HCC in the setting of steatohepatitis. In our Mount Sinai (New York) cohort, we found SH-HCC in 17/24 (71%) patients with NASH and in 14/19 (74%) patients with ASH, while SH-HCC was the predominant tumor morphology in 12/24 (50%) in the NASH group and 9/19 (47%) in the ASH group. Upon review, 12/19 patients diagnosed with ASH also had diabetes and/or a body mass index >30. When these patients were removed, we still found similar rates of SH-HCC (6/7 [86%] showed SH-HCC, while SH-HCC was predominant in 3/7 [43%]. Interestingly, glycogenated hepatocyte nuclei were seen in the nontumor liver in 4/7 (57%) of these cases. In our Japan cohort, we also found similar rates of SH-HCC in NASH and ASH patients with HCC, 15/58 (26%), and 16/45 (36%), respectively. We determined molecular subclassification of tumors from the Japan cohort and found no difference in the distribution of S1, S2 and S3 subclasses among the ASH and NASH groups, though, among cases of SH-HCC, there was a trend toward an association of ASH with S1 (P=0.054) and NASH with S3 (P=0.052). Our study shows that SH-HCC is common in both ASH and NASH and that both underlying liver diseases produce tumors with similar molecular profiles, though different pathways may underlie the development of SH-HCC in ASH versus NASH.

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 ß-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, ß-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.

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.

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.

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.

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

INTRODUCTION: '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.

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.