Genetic deletion or pharmacologic inhibition of the Nlrp3 inflammasome did not ameliorate experimental NASH.

It has been postulated that inflammasomes, in particular the NLRP3 (NLR family pyrin domain containing 3) inflammasome, mediate the necroinflammation and fibrosis that characterize nonalcoholic steatohepatitis (NASH) by engaging innate immune responses. We aimed to investigate the impact of genetic deletion or pharmacologic inhibition of the NLRP3 inflammasome on experimental steatohepatitis. Global Nlrp3 KO (expected to inhibit the NLRP3 inflammasome) or Casp1 KO (expected to inhibit all inflammasomes) mice were compared to wild type controls after 6 months on a high-fat, high-cholesterol (HFHC, 1% cholesterol) diet known to induce fibrosing steatohepatitis. Additionally, wildtype mice on a HFHC diet (0.75% or 0.5% cholesterol) for 6 months were either treated or not treated with an oral, pharmacologic inhibitor of Nlrp3 (MCC950) that was delivered in the drinking water (0.3 mg/ml). We found that genetic deletion or pharmacologic inhibition of the NLRP3 inflammasome did not ameliorate any of the histological components of fibrosing NASH in HFHC-fed mice. Collectively, these results do not support NLRP3 inhibition as a potential target for human NASH.

Centrizonal hepatocyte dropout in allograft liver biopsies: a clinicopathological study.

AIMS: Centrizonal hepatocyte dropout has been described in diverse liver pathologies, including viral hepatitis, venous outflow obstruction, and allograft cellular rejection. However, its clinical significance remains uncertain. METHODS AND RESULTS: We designed a clinicopathological study of 206 allograft liver biopsies with centrizonal hepatocyte dropout. Centrizonal hepatocyte dropout was associated most frequently with cellular rejection (n = 62), asymptomatic/protocol biopsies (n = 56), immediate post-transplantation biopsies (n = 21), biliary obstruction (n = 14), and viral hepatitis (n = 13). The differential diagnosis is informed by timing post-transplantation, biliary imaging and laboratory test results. 'Cholestatic' and 'hepatocytic' laboratory patterns were associated with biliary obstruction and cellular rejection, respectively. A mixed pattern peaking after biopsy was observed in viral hepatitis cases. In the context of cellular rejection, dropout was not associated with the time interval to normalisation of serum alanine aminotransferase (ALT), but was associated with shorter transplant-free survival (hazard ratio 4, P = 0.01) than that of histological severity-matched controls. In time zero allograft biopsies, time to ALT normalisation was prolonged (median, 15 versus 11 days, P = 0.002) in allografts with centrizonal dropout, with no effect on retransplant-free survival. CONCLUSIONS: Centrizonal hepatocyte dropout has low clinicopathological diagnostic specificity. However, it correlates with adverse clinical outcomes in allograft cellular rejection and time zero biopsies.

Perturbation of Wnt/ß-catenin signaling and sexual dimorphism in non-alcoholic fatty liver disease.

AIMS: The prevalence of non-alcoholic fatty liver disease (NAFLD) and its progression to non-alcoholic steatohepatitis (NASH) is higher in postmenopausal women than men. The aim of this study was to determine the molecular mechanisms underlying this sexual dimorphism in NAFLD. METHODS: A total of 24 frozen liver samples of both sexes (normal and NAFLD/NASH) were used in this study. Total RNAseq was first used to identify differentially expressed genes (DEGs) between samples. Enrichment analysis of Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome were used to analyze biological pathways. RT2 profiler polymerase chain reaction (PCR) arrays were used to identify genes associated with the biological pathways. Immunoblotting was used to validate protein expression of certain genes. RESULTS: We identified 4362 genes that are differentially expressed between NAFLD/NASH and normal samples; of those 745 genes were characterized as sex specific in NAFLD/NASH. Multiple pathway analysis platforms showed that Wnt-signaling is a candidate shared for a common biological pathway-associated with NAFLD/NASH. Using Wnt pathway focused PCR array we identified many genes involved in canonical pathway (Wnt/ß-catenin activation) such as CTNNB1, c-Myc and CCND2 are overexpressed in female cases, whereas these genes are either not detected or downregulated in male cases. Immunoblot analysis validated the expression of CTNNB1 in female cases but not in male protein samples. CONCLUSIONS: Our study suggests, for the first time, that the activation of canonical Wnt signaling could be one of the main pathways associated with sexual dimorphism in NAFLD and NASH.

Neutrophilic inflammation in gallbladder carcinoma correlates with patient survival: A case-control study.

Gallbladder carcinoma is an uncommon malignancy with an overall 5-year survival of less than 5%. Gallbladder carcinoma has been strongly linked with cholelithiasis and chronic inflammation. Case reports and series have described cholecystitis with acute (neutrophilic) inflammation in association with gallbladder carcinoma, although a clear relationship to patient outcome has not been established. Our series included 8 cases of gallbladder carcinoma with high tumor-associated neutrophils (>25 per high power field) that were associated with shorter patient survival (Cox regression coefficient 6.2, p = 0.004) than age- and stage-matched controls. High tumor-associated neutrophils were not associated with gallbladder rupture/perforation or increased bacterial load measured by 16S PCR. Neutrophilic inflammation with gallbladder carcinoma correlates to shorter survival, independent of patient age and stage of carcinoma. The findings suggest that the degree of neutrophilic inflammation may have prognostic significance in specimens from patients with gallbladder carcinoma after cholecystectomy. Further studies with larger case numbers are needed to confirm and generalize these findings.

Comparing the clinicopathological characteristics of combined hepatocellular-cholangiocarcinoma with those of other primary liver cancers by use of the updated World Health Organization classification.

AIMS: Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is an uncommon hepatic malignancy with a poor outcome. The 2019 World Health Organization (WHO) classification modified the definition and discarded the subtypes with stem cell features. However, the differences among cHCC-CCA, hepatocellular carcinoma (HCC), HCC with stem cell/progenitor features (HCCscf) and intrahepatic cholangiocarcinoma (iCCA) remain undetermined. The aim of this study was to investigate the characteristics of cHCC-CCA in comparison with those of other primary liver cancers by utilising the updated WHO classification. METHODS AND RESULTS: We retrospectively analysed 64 cHCC-CCA patients and 55 HCCscf patients from December 2007 to May 2018. Propensity score matching was conducted to compare these with HCC and iCCA patients. Clinicopathological characteristics, event-free survival and overall survival were evaluated with multivariate Cox proportional hazard regression. During a median follow-up of 55.9 months, cHCC-CCA patients had significantly poorer survival than HCCscf patients, and survival intermediate between that of HCC patients and that of iCCA patients. Hepatitis B virus (HBV) infection and high levels of tumour-infiltrating lymphocytes (TILs) were associated with favourable survival in cHCC-CCA patients. In the multivariate analysis, poor hepatic reserve, absence of HBV infection, stage IV disease and low levels of TILs were significant negative prognostic factors in cHCC-CCA patients. After being pooled with other primary liver cancers, cHCC-CCA and iCCA resulted in the worse survival. CONCLUSIONS: cHCC-CCA patients have survival intermediate between that of HCC patients and iCCA patients, and HBV infection and high levels of TILs predict favourable survival. Our study provides clinical correlations for the new 2019 WHO classification.

S100P as a marker for poor survival and advanced stage in gallbladder carcinoma.

AIMS: Gallbladder carcinomas usually present in advanced stages and has a dismal prognosis despite modern imaging techniques and aggressive surgical intervention. Identification of biologic markers for early diagnosis and improved therapeutic strategies is thus of paramount importance. S100P has been identified in a variety of malignant neoplasms of the gastrointestinal and pancreaticobiliary systems, but it is not yet known if S100P expression is associated with clinically-relevant characteristics of gall bladder carcinoma. The aims of the present study were: 1) to investigate the relationship between S100P expression and histological type, grade, tumor-node-metastasis stage, presence of vascular invasion, perineural invasion and necrosis; and 2) to evaluate for any S100P-defined difference in the risk for tumor recurrence or death. METHOD: Immunostains for S100P were performed on 4 tissue microarray blocks containing 91 cases of gall bladder carcinoma. RESULT: The intensity of S100P staining was significantly associated with pathological T stage 4 (p = 0. 0238). Staining intensity ≥3 in ≥25% tumor cells was associated with pathological T stage 4 (p = 0.0005). A higher S100P immunoreactivity score (IRS) was significantly associated with higher TNM stage (p = 0.0341). Age (p = 0.0485), presence of vascular invasion (p = 0.0359), pathological T stage (p = 0.0291) and TNM stage (p = 0.0153) were significantly associated with tumor recurrence. Intense S100P reactivity was associated with decreased overall survival [hazard ratio = 9.614; 95% confidence interval (CI), 1.873-49.338; p = 0.0067]. CONCLUSION: Our findings indicate that S100P over-expression is a potential prognostic marker for gall bladder carcinoma and is significantly associated with advanced tumor stage and poorer survival.

Non-alcoholic fatty liver disease: A review with clinical and pathological correlation.

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in North America and Europe, with increasing prevalence in other regions of the world. Its spectrum encompass steatosis, non-alcoholic steatohepatitis (NASH), fibrosis and cirrhosis. It is considered as the manifestation of metabolic syndrome in liver, and its development and progression is influenced by complex interaction of environmental and genetic factors. In this review we discuss the histopathological features, differential diagnoses, and the commonly used grading and staging systems of NAFLD. NAFLD associated with other diseases, histological changes after therapeutic intervention and recurrence or occurrence of NAFLD after liver transplantation are also addressed.

A Review on the Update of Combined Hepatocellular Cholangiocarcinoma.

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a primary liver tumor with neoplastic components of both hepatocytic and cholangiocytic differentiation. This unique neoplasm is gaining increasing recognition due to the intriguing pathology, tumor biology, and clinical behavior. It also poses challenges in diagnosis, treatment, and research, largely because of its histological and phenotypic diversity that lead to confusion in terminology and classification. There have been efforts attempting to unify the terminology of this neoplasm recently. Advances in investigation in various aspects have also been made. This review aims to update the terminology, classification, and clinical and pathological characteristics of cHCC-CCA.

Exercise retards hepatocarcinogenesis in obese mice independently of weight control.

BACKGROUND & AIMS: Obesity and type 2 diabetes increase hepatocellular carcinoma (HCC) incidence in humans and accelerate diethylnitrosamine (DEN)-induced hepatocarcinogenesis in mice. We investigated whether exercise reduces HCC development in obese/diabetic Alms1 mutant (foz/foz) mice and studied protective mechanisms. METHODS: We measured HCC development in DEN-injected male foz/foz and wild-type (WT) littermates housed with or without an exercise wheel from week 4 until 12 or 24 weeks, and in foz/foz mice pair-fed to WT littermates. We also studied HCC development in DEN-injected Jnk1-/-.foz/foz mice generated by cross breeding, as well as their genetic controls. Dysplastic hepatocytes were identified by glutathione-S-transferase pi form (GST-pi) immunohistochemistry, liver nodules were counted, and HCC was analysed by histopathology. RESULTS: Exercising foz/foz mice maintained similar weight as WT mice up to 10 weeks, but then gained weight and were obese by 24 weeks; a similar body weight profile was obtained by pair-feeding foz/foz mice to WT. At 12 weeks, livers of exercising foz/foz mice exhibited fewer GST-pi positive hepatocytes than sedentary counterparts; by 24 weeks, fewer exercising foz/foz mice developed HCC (15% vs. 64%, p <0.05). Conversely, pair-feeding foz/foz mice failed to reduce HCC incidence. In these insulin-resistant foz/foz mice, exercise failed to activate hepatic AMPK or Akt/mTORC1. Instead, it improved insulin sensitivity, ameliorated steatosis and liver injury, activated p53 to increase p27 expression, and prevented JNK activation. This was associated with suppression of hepatocellular proliferation. DEN-injected Jnk1-/-.foz/foz mice failed to develop liver tumours or HCC at 24 weeks. CONCLUSIONS: Direct effects of exercise dampen proliferation of dysplastic hepatocytes to reduce 3-month dysplastic foci and 6-month incidence of DEN-induced HCC in obese, insulin-resistant mice. The effects of exercise that potentially slow hepatocarcinogenesis include p53-mediated induction of p27 and prevention of JNK activation. LAY SUMMARY: Fatty liver disease commonly occurs alongside obesity and diabetes, contributing to rapidly increasing rates of liver cancer throughout the world. Herein, we show that exercise reduces the incidence and progression of hepatocellular carcinoma in mouse models. The effect of exercise on cancer risk was shown to be independent of changes in weight. Exercise could be a protective mechanism against liver cancer in at-risk individuals.

Mouse Models of Nonalcoholic Steatohepatitis: Toward Optimization of Their Relevance to Human Nonalcoholic Steatohepatitis.

Nonalcoholic steatohepatitis (NASH) arises from a variable interplay between environmental factors and genetic determinants that cannot be completely replicated in animals. Notwithstanding, preclinical models are needed to understand NASH pathophysiology and test mechanism-based therapies. Among several mouse models of NASH, some exhibit the key pathophysiologic as well as histopathologic criteria for human NASH, whereas others may be useful to address specific questions. Models based on overnutrition with adipose restriction/inflammation and metabolic complications, particularly insulin resistance, may be most useful to investigate critical etiopathogenic factors. In-depth pathologic description is required for all models. Some models demonstrate hepatocyte ballooning, which can be confused with microvesicular steatosis, whereas demonstration of an inflammatory infiltrate and pattern of liver fibrosis compatible with human NASH is desirable in models used for pharmacologic testing. When mice with specific genetic strains or mutations that cause overeating consume a diet enriched with fat, modest amounts of cholesterol, and/or simple sugars ("Western diet"), they readily develop obesity with liver disease similar to human NASH, including significant fibrosis. Purely dietary models, such as high-fat/high-cholesterol, Western diet, and choline-deficient, amino acid-defined, are similarly promising. We share concern about using models without weight gain, adipose pathology, or insulin resistance/hyperinsulinemia and with inadequate documentation of liver pathology. NASH-related fibrosis is a key endpoint in trials of possible therapies. When studied for this purpose, NASH models should be reproducible and show steatohepatitis (ideally with ballooning) and at least focal bridging fibrosis, while metabolic factors/disordered lipid partitioning should contribute to etiopathogenesis. Because murine models are increasingly used to explore pharmacologic therapies for NASH, we propose a minimum set of requirements that investigators, drug companies, and journals should consider to optimize their translational value.

Immune-related adverse reactions in the hepatobiliary system: second-generation check-point inhibitors highlight diverse histological changes.

AIMS: Immune check-point inhibitors are known to cause immune-mediated adverse liver injury, but our knowledge is mainly based on cases treated with ipilimumab or nivolumab. METHODS AND RESULTS: Clinicopathological features of 10 patients with hepatobiliary adverse reactions caused by second-generation drugs, pembrolizumab (n = 6) and atezolizumab (n = 4), were reviewed. Liver dysfunction developed during a median period of 3.5 weeks after administration of the check-point inhibitor (3 days-1 year). Antinuclear antibodies were detected in two patients at a low titre (1/80), and serum IgG concentrations were also only mildly elevated in two patients. Liver biopsies showed panlobular hepatitis (n = 5), cholangiopathic changes (n = 2), granulomatous injury (n = 2) and bland cholestasis (n = 1). Two cases of cholangiopathy (both pembrolizumab-treated) showed diffuse sclerosing cholangitis on imaging, and one also presented lymphocytic cholangitis resembling primary biliary cholangitis on biopsy. In two atezolizumab-treated cases, Küpffer cells were hyperplastic and aggregated, forming microgranulomas. Confluent necrosis and eosinophilic or plasma cell infiltration were rare. On immunostaining, the ratio of CD8+ /CD4+ cells was 12.2 ± 5.1, which was significantly higher than that in autoimmune hepatitis (2.7 ± 1.1; P < 0.001) or idiosyncratic drug-induced liver injury (5.0 ± 1.1; P = 0.014). All patients responded to steroid therapy, but it was less effective in patients with sclerosing cholangitis. CONCLUSIONS: Pembrolizumab and atezolizumab manifested not only lobular hepatitis but also sclerosing cholangitis, lymphocytic duct injury and granulomatous hepatitis, probably representing various impaired cellular functions in CD8+ lymphocytes and macrophages due to blockage of PD-1-PD-L1 interaction.

Prevalence, risk factors, and surveillance patterns for gastric intestinal metaplasia among patients undergoing upper endoscopy with biopsy.

BACKGROUND AND AIMS: Gastric intestinal metaplasia (GIM) is an important precursor lesion to gastric cancer (GC), the second leading cause of cancer death worldwide. There exist few data regarding the prevalence of, risk factors for, and clinical practice patterns regarding GIM in the United States. Furthermore, there are currently no U.S. guidelines regarding screening/surveillance for GIM. METHODS: All consecutive upper endoscopic procedures from 2 academic medical centers in Seattle between 1999 and 2014 were reviewed. Demographic, clinical, and endoscopic covariates were recorded at time of endoscopy. Procedures with gastric biopsy were matched to final the histologic diagnoses, including the presence of Helicobacter pylori. Cases of GIM and dysplasia were recorded and compared with non-GIM controls using univariate and multivariable regression. Surveillance patterns for cases of GIM were recorded. RESULTS: Data from 36,799 upper endoscopies, 17,710 gastric biopsies, 2073 cases of GIM, 43 cases of dysplasia, and 78 cases of GC were captured. The point prevalence of GIM was 11.7% in patients who underwent gastric biopsy. Non-white race (P < .001), increasing age (P < .001), and presence of H pylori (P < .001) were associated with GIM. If GIM was present, increasing age (P < .001) and male gender (P < .001) were associated with progression, and the presence of H pylori (P < .001) was inversely associated with progression to dysplasia/GC. Few cases of GIM/dysplasia/GC were identified during procedures for GIM screening/surveillance. Only 16% of patients with a diagnosis of GIM received a recommendation for surveillance. CONCLUSIONS: There is a high prevalence of GIM among non-white and Hispanic Americans. Risk factors for development of GIM may be distinct from the risk factors for progression to GC.

Loss of nectin-3 expression as a marker of tumor aggressiveness in pancreatic neuroendocrine tumor.

Pancreatic neuroendocrine tumors (PanNETs) are rare, and prediction of aggressive characteristics, such as recurrence and metastasis and prognosis of PanNETs remain difficult. Nectins are cell adhesion molecules that regulate the formation of adherens and tight junctions. In this study, we investigated the clinicopathological significance of nectin-3 expression in patients with PanNETs. Immunohistochemical analysis of nectin-3 expression was performed on 78 cases of PanNET. Low nectin-3 expression in the membrane (positive ratio ≤25%) was observed in 62 cases (79.5%) and was significantly correlated with larger tumor size (>20 mm; P = 0.003), G2/G3 tumors (P = 0.025), higher Ki67 labeling index (≥3%; P = 0.009), lymphatic involvement (P = 0.047), advanced pT-factor (T2-T4; P = 0.003), lymph node metastasis (P = 0.006), advanced Union for International Cancer Control/American Joint Committee on Cancer-stage (Stage II-IV; P = 0.001), advanced ENETS stage (Stage IIa-IV; P = 0.001), nonfunctioning tumors (P = 0.002), and a shorter disease-free survival (P = 0.019). However, there was no significant correlation between nectin-3 expression in the membrane and/or cytoplasm and the clinicopathological parameters. The present results suggest that decreased nectin-3 expression in the membrane is associated with increased tumor aggressiveness of PanNETs. Clinically, immunohistochemical analysis of nectin-3 may help predict tumor aggressiveness for PanNETs.

Knowledge gaps in the appendix: a multi-institutional study from seven academic centers.

Appendix pathology represents uncommonly encountered specimens with unique diagnostic challenges. To delineate common knowledge gaps, extramural consults submitted to seven institutions between 2016-2017 were reviewed. All appendix consults were resections (100%, n = 43), and the majority were directed for consultation by the originating pathologist (95%, n = 41) with no additional studies performed by the consultant (65%, n = 28). This study was dominated by inquiries related to low grade appendiceal mucinous neoplasms (44%, n = 19) and goblet cell carcinoid related neoplasms (19%, n = 8). Of the 43 appendiceal consults, 19 were submitted by the contributing pathologist as low grade appendiceal mucinous neoplasm, but only half of these were diagnosed by the consultant as such (n = 9). Low grade appendiceal mucinous neoplasm-related consultation themes included diverticular disease, criteria for invasion, high grade atypia, extra-appendiceal mucin, and staging. Examples of major disagreements that were downgraded included consults submitted as low grade appendiceal mucinous neoplasm and diagnosed by the consultant as serrated polyp (n = 3), appendicitis (n = 1), and benign appendix (n = 1). Examples of major disagreements-upgraded included cases submitted as low grade appendiceal mucinous neoplasm and diagnosed by the consultant as low grade appendiceal mucinous neoplasm with high-risk features (n = 2) and mucinous adenocarcinoma (n = 2). One case contained both a major disagreement-upgrade (low grade appendiceal mucinous neoplasm changed to high grade appendiceal mucinous neoplasm) and a major disagreement-downgrade (pT3 changed to Tis). Of the 15 cases diagnosed by the consultants as low grade appendiceal mucinous neoplasm, submitted diagnoses included low grade appendiceal mucinous neoplasm (n = 9), adenocarcinoma (n = 5), and one case was submitted without a diagnosis. For goblet cell carcinoid-related consults, the usual inquiry related to distinguishing goblet cell carcinoid from goblet cell carcinoid with adenocarcinoma (adenocarcinoma ex-goblet cell carcinoid). Of the 38 overall consults with a submitted diagnosis, 53% (n = 20) were disagreements, and most of these were major disagreements-downgraded (n = 13).

Checkpoint inhibitor-induced liver injury: A novel form of liver disease emerging in the era of cancer immunotherapy.

Liver injury triggered by immune checkpoint inhibitors has been increasingly seen in clinical practice, and the incidence is likely to rise further in the next several years because of expanded indications for cancer immunotherapy. Tissue damage driven by disrupted immune tolerance against self-antigens is called an immune-related adverse event (irAE). irAEs in the liver histologically presents panlobular hepatitis (∼70%), isolated central zonal necrosis (∼20%), primarily granulomatous hepatitis (∼5%), and other minor forms of tissue injury (∼5%). Infiltrating cells are mainly lymphocytes and occasional eosinophils. Unlike classic autoimmune hepatitis (AIH), plasma cell infiltration is not conspicuous. Immunostaining reveals a large number of CD8+ T lymphocytes and a markedly smaller number of CD4+ cells or CD20+ B lymphocytes. The unique CD3+/CD20+ and CD4+/CD8+ ratios shifted in favor of CD8+ cytotoxic T lymphocytes are helpful to discriminate irAEs from other conditions (e.g., AIH, idiosyncratic drug-induced liver injury). Another hepatobiliary manifestation of irAEs is sclerosing cholangitis clinically characterized by elevations of biliary enzymes, diffuse duct wall thickening, and duct dilatation. Lymphocytic infiltration can be observed by endoscopic biopsies from the thick extrahepatic bile ducts, and liver needle biopsies may also show severe lymphocytic cholangitis resembling primary biliary cholangitis. An important differential diagnosis of irAEs is previously asymptomatic or subclinical liver disease unmasked by cancer immunotherapy, which is often challenging and requires close clinicopathological correlations.

Update on the pathology of liver neoplasms.

Many advances have developed in the pathology of liver tumors in the recent decade. Examples of these advances include the use of glutamine synthetase in the diagnosis of focal nodular hyperplasia, subtyping of hepatocellular adenomas using molecular and immunohistochemical methods, the unraveling of the fusion transcript between the DNAJB1 gene and the PRKACA gene in fibrolamellar carcinoma, and the more unified classification and terminology in intrahepatic bile duct tumors and their precursor lesions. Nevertheless, challenges still remain, e.g., the differential diagnosis between well-differentiated hepatocellular carcinoma and hepatocellular adenoma; distinction among poorly differentiated hepatocellular carcinoma, cholangiocarcinoma and metastatic neoplasm; terminology of the combined hepatocellular carcinoma-cholangiocarcinoma, etc. This review aims to address updates in the pathologic diagnosis and clinical relevance of tumors of the liver and intrahepatic bile ducts in adults and their differential diagnosis and diagnostic pitfalls.

Hepatotoxicity of immune checkpoint inhibitors: a histology study of seven cases in comparison with autoimmune hepatitis and idiosyncratic drug-induced liver injury.

The adverse effects of immune checkpoint inhibitors in various organs may be attributed to immune-mediated processes triggered by disrupted self-tolerance; however, it remains unclear whether they are similar or dissimilar to classic organ-specific autoimmune diseases. The present study aimed to compare clinicopathologic features between checkpoint inhibitor-induced liver injury and acutely presenting autoimmune hepatitis or idiosyncratic drug-induced liver injury. Seven patients treated with nivolumab (n = 5) or ipilimumab (n = 2) presented with liver dysfunction a median of 41 days (range 21-120) after the initiation of immunotherapy. All patients had elevated liver enzymes, whereas hyper-bilirubinemia was less common. None of the patients had antinuclear antibodies or IgG elevations. Stopping the immunotherapy and additional immunosuppression with corticosteroids normalized or decreased liver enzymes in all patients treated. Histologically, all biopsies showed predominantly lobular hepatitis with milder portal inflammation. Centrilobular confluent necrosis and plasmacytosis were observed in a single case, and were markedly less common and milder than those in autoimmune hepatitis (p = 0.017 and p < 0.001, respectively). Bile duct injury, micro-abscesses, and extramedullary hematopoiesis were also found in one case each. Immunostaining revealed the presence of large numbers of CD3+ and CD8+ lymphocytes, whereas CD20+ B cells and CD4+ T cells were fewer in checkpoint inhibitor-induced liver injury than in autoimmune hepatitis or drug-induced liver injury. In conclusion, liver injury caused by cancer immunotherapy shares some features with injury of autoimmune hepatitis; however, there are obvious differences between the two conditions. Checkpoint inhibitor-induced liver injury may represent an immune-mediated, less zone-selective hepatocyte necrosis not requiring the strong activation of helper T cells and immunoglobulin production.

Molecular testing for the clinical diagnosis of fibrolamellar carcinoma.

Fibrolamellar carcinoma has a distinctive morphology and immunophenotype, including cytokeratin 7 and CD68 co-expression. Despite the distinct findings, accurate diagnosis of fibrolamellar carcinoma continues to be a challenge. Recently, fibrolamellar carcinomas were found to harbor a characteristic somatic gene fusion, DNAJB1-PRKACA. A break-apart fluorescence in situ hybridization (FISH) assay was designed to detect this fusion event and to examine its diagnostic performance in a large, multicenter, multinational study. Cases initially classified as fibrolamellar carcinoma based on histological features were reviewed from 124 patients. Upon central review, 104 of the 124 cases were classified histologically as typical of fibrolamellar carcinoma, 12 cases as 'possible fibrolamellar carcinoma' and 8 cases as 'unlikely to be fibrolamellar carcinoma'. PRKACA FISH was positive for rearrangement in 102 of 103 (99%) typical fibrolamellar carcinomas, 9 of 12 'possible fibrolamellar carcinomas' and 0 of 8 cases 'unlikely to be fibrolamellar carcinomas'. Within the morphologically typical group of fibrolamellar carcinomas, two tumors with unusual FISH patterns were also identified. Both cases had the fusion gene DNAJB1-PRKACA, but one also had amplification of the fusion gene and one had heterozygous deletion of the normal PRKACA locus. In addition, 88 conventional hepatocellular carcinomas were evaluated with PRKACA FISH and all were negative. These findings demonstrate that FISH for the PRKACA rearrangement is a clinically useful tool to confirm the diagnosis of fibrolamellar carcinoma, with high sensitivity and specificity. A diagnosis of fibrolamellar carcinoma is more accurate when based on morphology plus confirmatory testing than when based on morphology alone.

Increased expression of senescence-associated cell cycle regulators in the progression of biliary atresia: an immunohistochemical study.

AIMS: Cellular senescence plays a role in tumour suppression and in the pathogenesis of various non-neoplastic diseases, including primary biliary cholangitis and other adult cholangiopathies. Less is known about the role of cellular senescence in cholangiopathies in children. With that in mind, we examined the expression of senescence-associated cell cycle regulators in biliary atresia, the most common form of paediatric obliterative cholangiopathy. METHODS AND RESULTS: The expression of senescence-associated cell cycle regulators (p16Ink4a and p21WAF1/Cip1 ) and a ductular reaction related marker (neural cell adhesion molecule: NCAM) was examined in bile ducts and bile ductules in liver samples taken from the patients with biliary atresia [n = 80; including 23 samples at the time of the Kasai procedure (KP) and 63 obtained from the explanted liver (LT) (six cases with samples at both surgical stages of disease)] and from appropriate controls (n = 17). The degree of ductular reaction and cholestasis was significantly more extensive in LT than KP (P < 0.01). The expression of p16INK4a and NCAM was significantly more extensive in bile ducts and bile ductules in ductular reaction in both KP and LT compared to controls and in LT compared to KP (P < 0.05). The expression of p21WAF1/Cip1 was significantly more extensive in bile ducts and bile ductules in KP compared to both LT and controls (P < 0.01). CONCLUSIONS: Cellular senescence may play a role in the progression of bile duct loss in biliary atresia in a manner similar to that of adult cholangiopathies.

Data set for the reporting of intrahepatic cholangiocarcinoma, perihilar cholangiocarcinoma and hepatocellular carcinoma: recommendations from the International Collaboration on Cancer Reporting (ICCR).

Optimal patient management benefits from comprehensive and accurate pathology reports that contribute to cancer staging and prognostication. Proforma reports are used in many countries, but these vary in their structure and implementation. The International Collaboration on Cancer Reporting (ICCR) is an alliance formed by the Royal College of Pathologists of Australasia, the Royal College of Pathologists of the United Kingdom, the College of American Pathologists, the Canadian Partnership Against Cancer the European Society of Pathology and the American Society of Clinical Pathology (ASCP), with the aim of developing an evidence-based reporting data set for each cancer site. It is argued that this should reduce the global burden of cancer data set development and reduplication of effort by different international institutions that commission, publish and maintain standardised cancer reporting data sets. The resultant standardisation of cancer reporting will benefit not only those countries directly involved in the collaboration but also others not in a position to develop their own data sets. We describe the development of a cancer data set by the ICCR expert panel for the reporting of the main malignant liver tumours: intrahepatic cholangiocarcinoma, perihilar cholangiocarcinoma and hepatocellular carcinoma and present the 'required' and 'recommended' elements to be included in the report with an explanatory commentary. This data set incorporates definitions and classifications in the most recent World Health Organisation (WHO) publication on hepatic malignancies (4th edition) and the recently published tumour-node-metastasis (TNM)8 staging system. Widespread adoption and implementation of this data set will enable consistent and accurate data collection, comparison of epidemiological and pathological parameters between different populations, facilitate research and ultimately result in better patient outcomes.