The diagnostic value of arginase-1 immunostaining in differentiating hepatocellular carcinoma from metastatic carcinoma and cholangiocarcinoma as compared to HepPar-1

Cholangiocarcinoma: Pathologic and Molecular Classification in the Era of Precision Medicine

CONTEXT.—

Cholangiocarcinoma (CCA) is a heterogeneous cancer of the bile duct, and its diagnosis is often challenging.

OBJECTIVE.—

To provide insights into state-of-the-art approaches for the diagnosis of CCA.

DATA SOURCES.—

Literature review via PubMed search and authors' experiences.

CONCLUSIONS.—

CCA can be categorized as intrahepatic or extrahepatic. Intrahepatic CCA is further classified into small-duct-type and large-duct-type, whereas extrahepatic CCA is classified into distal and perihilar according to site of origin within the extrahepatic biliary tree. Tumor growth patterns include mass forming, periductal infiltrating, and intraductal tumors. The clinical diagnosis of CCA is challenging and usually occurs at an advanced tumor stage. Pathologic diagnosis is made difficult by tumor inaccessibility and challenges in distinguishing CCA from metastatic adenocarcinoma to the liver. Immunohistochemical stains can assist in differentiating CCA from other malignancies, such as hepatocellular carcinoma, but no distinctive CCA-specific immunohistochemical profile has been identified. Recent advances in next-generation sequencing-based high-throughput assays have identified distinct genomic profiles of CCA subtypes, including genomic alterations that are susceptible to targeted therapies or immune checkpoint inhibitors. Detailed histopathologic and molecular evaluations of CCA by pathologists are critical for correct diagnosis, subclassification, therapeutic decision-making, and prognostication. The first step toward achieving these goals is to acquire a detailed understanding of the histologic and genetic subtypes of this heterogeneous tumor group. Here, we review state-of-the-art approaches that should be applied to establish a diagnosis of CCA, including clinical presentation, histopathology, staging, and the practical use of genetic testing methodologies.

Arginase-1 is More Specific Than Hepatocyte Paraffin 1 for Differentiating Hepatocellular Carcinomas With Cytoplasmic Clearing from Nonhepatocellular Clear Cell Tumors in Liver Biopsies

Arginase-1 (Arg1) and hepatocyte paraffin antigen 1 (HepPar1) are specific and sensitive markers of hepatocellular differentiation. HepPar1 is a granular cytoplasmic immunostain that may be negative in hepatocellular carcinoma (HCC) with cytoplasmic clearing. Arg1 shows uniform cytoplasmic positivity and frequent nuclear positivity. This study was undertaken to determine the staining pattern of Arg1 in HCC with cytoplasmic clearing and compare its use to HepPar1. Fifteen resected HCCs with cytoplasmic clearing and 31 biopsies of clear cell liver tumors (14 HCCs and 17 nonhepatocellular tumors) were identified. Resections were stained with Arg1 to characterize the pattern, intensity, and extent of Arg1 positivity. Biopsies were stained with Arg1 (n=31) and HepPar1 (n=28). In all, 13/15 resected and 11/14 biopsied HCCs with cytoplasmic clearing showed nuclear positivity for Arg1. Both Arg1 and HepPar1 stained significantly more HCCs than nonhepatocellular tumors (13/14 and 11/12, respectively, with P <0.0001 and P =0.0018, respectively). However, HepPar1 stained significantly more nonhepatocellular tumors (5/12) than Arg1 (0/17, P =0.0445). Arg1 frequently displayed nuclear positivity, and interobserver agreement was better for Arg1 ( K =0.93 vs. 0.79). Overall, Arg1 is more specific than HepPar1 for differentiating HCC with cytoplasmic clearing from nonhepatocellular clear cell tumors in the liver. Its staining characteristics, including nuclear positivity, make it easier to interpret in combination with morphology, improving interobserver variability, and it stains significantly fewer mimics than HepPar1.

An Update on the Role of Immunohistochemistry in the Evaluation of Pancreatic/Liver/Gastrointestinal Luminal Tract Disorders

CONTEXT.—

Immunohistochemistry serves as an ancillary diagnostic tool for a wide variety of neoplastic and nonneoplastic disorders, including infections, workup of inflammatory conditions, and subtyping neoplasms of the pancreas/liver/gastrointestinal luminal tract. In addition, immunohistochemistry is also used to detect a variety of prognostic and predictive molecular biomarkers for carcinomas of the pancreas, liver, and gastrointestinal luminal tract.

OBJECTIVE.—

To highlight an update on the role of immunohistochemistry in the evaluation of pancreatic/liver/gastrointestinal luminal tract disorders.

DATA SOURCES.—

Literature review and authors' research data and personal practice experience were used.

CONCLUSIONS.—

Immunohistochemistry is a valuable tool, assisting in the diagnosis of problematic tumors and benign lesions of the pancreas, liver, and gastrointestinal luminal tract, and also in the prediction of prognosis and therapeutic response for carcinomas of the pancreas, liver, and gastrointestinal luminal tract.

Ancillary tests for hepatobiliary neoplasms: what we know and what we need to know

Ancillary tests are commonly used in the surgical pathology setting for diagnosing challenging neoplastic diseases of the liver and biliary tract, while histology and clinical correlation remain to be critically important. With continuous discoveries, more and more useful ancillary tests have become available, which can help distinguish between malignant and benign hepatocellular neoplasms, malignant and benign biliary tract entities, and intrahepatic and metastatic carcinomas. This review will focus on existing and emerging biomarkers (such as glutamine synthetase, organic anion transporting polypeptide 1B3, insulin-like growth factor-II mRNA binding protein-3, S100P, SMAD4, enhancer of zeste homolog 2, albumin, hepatocyte nuclear factor-1β, etc.) that can be used for the diagnosis, classification and prognostication of hepatobiliary neoplasms.

Combined Salivary Proteome Profiling and Machine Learning Analysis Provides Insight into Molecular Signature for Autoimmune Liver Diseases Classification

Autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) are autoimmune liver diseases that target the liver and have a wide spectrum of presentation. A global overview of quantitative variations on the salivary proteome in presence of these two pathologies is investigated in this study. The acid-insoluble salivary fraction of AIH and PBC patients, and healthy controls (HCs), was analyzed using a gel-based bottom-up proteomic approach combined with a robust machine learning statistical analysis of the dataset. The abundance of Arginase, Junction plakoglobin, Desmoplakin, Hexokinase-3 and Desmocollin-1 decreased, while that of BPI fold-containing family A member 2 increased in AIHp compared to HCs; the abundance of Gelsolin, CD14, Tumor-associated calcium signal transducer 2, Clusterin, Heterogeneous nuclear ribonucleoproteins A2/B1, Cofilin-1 and BPI fold-containing family B member 2 increased in PBCp compared to HCs. The abundance of Hornerin decreased in both AIHp and PBCp with respect to HCs and provided an area under the ROC curve of 0.939. Machine learning analysis confirmed the feasibility of the salivary proteome to discriminate groups of subjects based on AIH or PBC occurrence as previously suggested by our group. The topology-based functional enrichment analysis performed on these potential salivary biomarkers highlights an enrichment of terms mostly related to the immune system, but also with a strong involvement in liver fibrosis process and with antimicrobial activity.

Isorhamnetin exerts anti-tumor activity in DEN + CCl4-induced HCC mice

BACKGROUND

Hepatocellular carcinoma (HCC) is the most prevalent type of liver cancer and the main cause of cancer death globally. The use of medicinal herbs as chemotherapeutic agents in cancer treatment is receiving attention as they possess no or minimum side effects. Isorhamnetin (IRN), a flavonoid, has been under attention for its anti-inflammatory and anti-proliferative properties in a number of cancers, including colorectal, skin, and lung cancers. However, the in vivo mechanism of isorhamnetin to suppress liver cancer has yet to be explored.

METHODS AND RESULT

HCC was induced by N-diethylnitrosamine (DEN) and carbon tetrachloride (CCL₄) in Swiss albino mice. Isorhamnetin (100 mg/kg body weight) was given to examine its anti-tumor properties in HCC mice model. Histological analysis and liver function assays were performed to assess changes in liver anatomy. Probable molecular pathways were explored using immunoblot, qPCR, ELISA, and immunohistochemistry techniques. Isorhamnetin inhibited various pro-inflammatory cytokines to suppress cancer-inducing inflammation. Additionally, it regulated Akt and MAPKs to suppress Nrf2 signaling. Isorhamnetin activated PPAR-γ and autophagy while suppressing cell cycle progression in DEN + CCl₄-administered mice. Additionally, isorhamnetin regulated various signaling pathways to suppress cell proliferation, metabolism, and epithelial-mesenchymal transition in HCC.

CONCLUSION

Regulating diverse cellular signaling pathways makes isorhamnetin a better anti-cancer chemotherapeutic candidate in HCC. Importantly, the anti-TNF-α properties of isorhamnetin could prove it a valuable therapeutic agent in sorafenib-resistant HCC patients. Additionally, anti-TGF-β properties of isorhamnetin could be utilized to reduce the EMT-inducing side effects of doxorubicin.

Criteria for preclinical models of cholangiocarcinoma: scientific and medical relevance

Cholangiocarcinoma (CCA) is a rare malignancy that develops at any point along the biliary tree. CCA has a poor prognosis, its clinical management remains challenging, and effective treatments are lacking. Therefore, preclinical research is of pivotal importance and necessary to acquire a deeper understanding of CCA and improve therapeutic outcomes. Preclinical research involves developing and managing complementary experimental models, from in vitro assays using primary cells or cell lines cultured in 2D or 3D to in vivo models with engrafted material, chemically induced CCA or genetically engineered models. All are valuable tools with well-defined advantages and limitations. The choice of a preclinical model is guided by the question(s) to be addressed; ideally, results should be recapitulated in independent approaches. In this Consensus Statement, a task force of 45 experts in CCA molecular and cellular biology and clinicians, including pathologists, from ten countries provides recommendations on the minimal criteria for preclinical models to provide a uniform approach. These recommendations are based on two rounds of questionnaires completed by 35 (first round) and 45 (second round) experts to reach a consensus with 13 statements. An agreement was defined when at least 90% of the participants voting anonymously agreed with a statement. The ultimate goal was to transfer basic laboratory research to the clinics through increased disease understanding and to develop clinical biomarkers and innovative therapies for patients with CCA.

Pathology of Combined Hepatocellular Carcinoma-Cholangiocarcinoma: An Update

Combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA) is a rare primary liver cancer that is composed of both hepatocellular and cholangiocellular differentiated cells. It is slightly more common in men and among Asian and Pacific islanders. Overall, risk factors are similar to classic risk factors of hepatocellular carcinoma (HCC). The classification has significantly evolved over time. The last WHO classification (2019) mainly emphasized diagnosis on morphological basis with routine stainings, discarded previously recognized classifications with carcinomas with stem cell features, introduced intermediate cell carcinoma as a specific subtype and considered cholangiolocarcinoma as a subtype of cholangiocellular carcinoma. Immunohistochemical markers may be applied for further specification but have limited value for diagnosis. Recent discoveries in molecular pathway regulation may pioneer new therapeutic approaches for this poor prognostic and challenging diagnosis.

Carcinoma of Unknown Primary Origin: Application of Immunohistochemistry With Emphasis to Different Cytokeratin 7 and 20 Staining Patterns

BACKGROUND

Although the primary origin of some carcinomas may be obscure to clinicians, its identification is crucial as it affects prognosis and treatment (especially novel targeted therapies). Immunohistochemistry (IHC) may be helpful in identifying the primary origin of carcinomas. This retrospective survey aimed to evaluate the frequency and accuracy of each IHC marker used to determine the origin of carcinomas.

METHODS

The review of pathology department archives revealed 307 cases of cancer of unknown primary origin (CUP) between 2015 and 2020, which were accessible in the department archives. Demographic information, site of biopsy, clinical and pathologic diagnoses, and IHC results of the patients were collected.

RESULTS

The patients included 157 (51.15%) men and 150 (48.85%) women. The age of the patients ranged from 14 to 92 years, including 106 (34.5%) expired cases. In 27% of cases, the primary origin of carcinoma remained unknown. The agreement between pathologic and clinical diagnoses was 59%. The most common pattern of cytokeratin (CK) expression in CUP was CK7+/CK20- (55.3%), followed by CK7-/CK20- (19%), CK7+/CK20+ (15%), and CK7-/CK20+ (10.7%), respectively.

CONCLUSION

The IHC analysis may improve the diagnosis of CUPs. However, the origin of some cases remains unknown despite an IHC analysis, thereby necessitating the use of more diagnostic procedures or gene expression studies for reaching a definitive diagnosis.

Decreased ARG1 expression as an adverse prognostic phenotype in non-alcoholic non-virus-related hepatocellular carcinoma

The incidence of non-alcoholic non-virus-related hepatocellular carcinoma (NANV-HCC) is increasing along with the growing prevalence of metabolic disorders. In this subset, few useful biomarkers are available to narrow down the high-risk group for recurrence. This study aimed to evaluate the prognostic impact of decreased ARG1 (arginase-1), which is pathologically known as a marker reflecting hepatocyte differentiation, in NANV-HCC. Besides, its relationship with biliary/progenitor cell markers, whose expressions are associated with poor prognosis, was also assessed. To reveal the clinicopathological association of decreased ARG1 expression in NANV-HCC, we investigated 99 patients who underwent curative-intent hepatectomy for NANV-HCC. Tissue microarrays were employed for immunohistochemical analysis. A total of 21 NANV-HCC cases (21%; 21/99) showed decreased ARG1 expression. Decreased ARG1 expression was an independent prognostic factor for both poor DFS (hazard ratio 2.17; 95% confidence interval 1.15-4.09; p = 0.02) and OS (hazard ratio 4.09; 95% confidence interval 1.71-9.80; p = 0.002). In addition, decreased ARG1 expression was significantly associated with expressions of biliary/progenitor cell markers, CK19 and CD56 (p < 0.01). As cytologic features of tumor cells, decreased ARG1 expression was significantly associated with lipid-less cytologic morphology (p = 0.045). These findings indicate that decreased ARG1 expression is a predictive phenotype of postoperative recurrence with poor prognosis in patients with NANV-HCC. Decreased ARG1 expression may be a precursor or overlapping feature with biliary/progenitor cell marker expressions in NANV-HCC.

Large-Scale Tissue Microarray Evaluation Corroborates High Specificity of High-Level Arginase-1 Immunostaining for Hepatocellular Carcinoma

Arginase-1 catalyzes the conversion of arginine to ornithine and urea. Because of its predominant expression in hepatocytes, it serves as a marker for hepatocellular carcinoma, although other tumor entities can also express arginase-1. To comprehensively determine arginase-1 expression in normal and neoplastic tissues, tissue microarrays containing 14,912 samples from 117 different tumor types and 608 samples of 76 different normal tissue types were analyzed by immunohistochemistry. In normal tissues, arginase-1 was expressed in the liver, the granular layer of the epidermis, and in granulocytes. Among tumors, a nuclear and cytoplasmic arginase-1 immunostaining was predominantly observed in hepatocellular carcinoma, where 96% of 49 cancers were at least moderately positive. Although 22 additional tumor categories showed occasional arginase immunostaining, strong staining was exceedingly rare in these entities. Staining of a few tumor cells was observed in squamous cell carcinomas of various sites. Staining typically involved maturing cells with the beginning of keratinization in these tumors and was significantly associated with a low grade in 635 squamous cell carcinomas of various sites (p = 0.003). Teratoma, urothelial carcinoma and pleomorphic adenomas sometimes also showed arginase expression in areas with squamous differentiation. In summary, arginase-1 immunohistochemistry is highly sensitive and specific for hepatocellular carcinoma if weak and focal staining is disregarded.

Scirrhous Hepatocellular Carcinoma: Systematic Review and Pooled Data Analysis of Clinical, Radiological, and Histopathological Features

Background

Aberrant subtypes of hepatocellular carcinoma (HCC) account for 20–30% of all HCCs and habitually present a challenge in diagnosis and treatment. Scirrhous hepatocellular carcinoma (s-HCC) is often misdiagnosed as cholangiocarcinoma, fibrolamellar hepatocellular carcinoma, or metastasis.

Methods

Electronic databases (PubMed, Web of Knowledge, Google Scholar, Cochrane Library, and WHO International Clinical Trials Registry Platform) were searched for publications on scirrhous hepatocellular carcinoma without date or language restrictions. Quality assessment was performed using a tool proposed by Murad et al for case reports and series. For observational studies, MINORS quality assessment tool was used. This study was registered at PROSPERO (CRD42020212323).

Results

S-HCC arises in patients with chronic hepatitis (hepatitis B in 60% and hepatitis C in 21%). S-HCC primarily affects men with a mean age of 55.8 years. Serum AFP is elevated above 20IU/mL in 66.7% of the patients. On ultrasound, s-HCC presents as hypoechoic or mosaic pattern lesions (47.6% each) and causes a retraction of the liver surface (70%) when near the capsule. Delayed enhancement of the tumor is evident in 87.0%. On MRI, 65.0% of s-HCCs show a target appearance. Histopathologic pattern is mostly irregular (97.6%). Lesions show a bulging appearance (100%), septae (85.6%) and a central scar (63.5%), and usually lack central necrosis (75%). Immunohistochemistry shows HepPar 1 positivity in 64.6%, CK7 in 40.7%, and EMA in 41.9%. The 5-year overall survival rate estimates 45.2% and 45.5% of the patients experience a recurrence after hepatectomy.

Conclusion

S-HCC is a rare subtype of HCC primarily arising in hepatitis- or cirrhosis-afflicted livers and incorporates atypical radiological and histopathological HCC features. Despite lower recurrence rates, overall survival of patients with s-HCC is poorer than generally for HCC, underlining the need for individualized treatment. Patients with atypical lesions of the liver should be referred to tertiary hospitals for interdisciplinary assessment and treatment.

The prognostic value of arginase-1 and glypican-3 expression levels in patients after surgical intrahepatic cholangiocarcinoma resection

Background

The aim of this study was to investigate the prognostic value of arginase-1 (Arg-1) and glypican-3 (GPC-3) in patients with intrahepatic cholangiocarcinoma (ICC).

Methods

Two hundred and thirty-seven patients with ICC were included in this study. All patients had undergone radical surgery and had complete clinical information. Immunohistochemistry was used to assess the levels of Arg-1 and GPC-3 in ICC tissues. Univariate and multivariate analyses were conducted to identify independent risk factors in ICC. The relationship between Arg-1 and GPC-3 levels and patient survival was determined using the Kaplan-Meier method.

Results

High Arg-1 and GPC-3 expression levels were associated with poor prognosis in patients with ICC, and they could be as new prognostic biomarkers in ICC.

Conclusion

Arg-1 and GPC-3 can serve as independent prognostic biomarkers in ICC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02426-9.

Arginase-1 and P-glycoprotein are downregulated in canine hepatocellular carcinoma

Background

Hepatocellular carcinoma is the most common primary hepatic malignancy in humans and dogs. Several differentially expressed molecules have been studied and reported in human hepatocellular carcinoma and non-neoplastic liver lesions. However, studies on the features of canine hepatocellular carcinoma are limited, especially related to the differential characteristics of neoplastic and non-neoplastic lesions.

Objectives

The study's objective was 1) to examine and evaluate the expression of arginase-1, P-glycoprotein, and cytokeratin 19 in canine liver tissues and 2) to investigate the differential features of hepatocellular carcinomas, liver tissue with non-neoplastic lesions, and paracancerous liver tissues in dogs.

Methods

The expression levels of three markers underwent immunohistochemical analysis in 40 non-neoplastic liver tissues, 32 hepatocellular carcinoma tissues, and 11 paracancerous liver tissues. Scoring of each marker was performed semi-quantitatively.

Results

Arginase-1 and P-glycoprotein were significantly downregulated in hepatocellular carcinoma, compared with hepatic tissues with non-neoplastic diseases (p < 0.001). Expression levels of arginase-1 and P-glycoprotein were also significantly lower in hepatocellular carcinoma than in paracancerous liver tissues (arginase-1, p = 0.0195; P-glycoprotein, p = 0.047). Few cytokeratin 19-positive hepatocytes were detected and only in one hepatocellular carcinoma and one cirrhotic liver sample.

Conclusions

The results of this study suggest that downregulation of arginase-1 and P-glycoprotein is a feature of canine hepatocellular carcinoma; thus, those markers are potential candidates for use in differentiating hepatocellular carcinomas from non-neoplastic liver lesions in dogs.

The strength of cytomorphology and efficacy of immuno-cytochemistry in distinguishing hepatocellular carcinoma from its mimics on fine-needle aspiration cytology

BACKGROUND

Cytomorphologic distinction of hepatocellular carcinoma (HCC) from its mimics on fine-needle aspiration cytology (FNAC) is often problematic. The present study evaluates the strength of cytomorphology and the utility of an immuno-panel of arginase-1, glypican-3, HepPar-1, thyroid transcription factor (TTF-1) and CK-19 in resolving this diagnostic issue.

METHODS

FNAC features of 71 nodular hepatic lesions were studied with an immunocyto/ histochemical (ICC/IHC) panel of arginase-1, glypican-3, HepPar-1, TTF-1 taking 10% positivity as "cut-off." Cytomorpholologic diagnoses were compared with diagnoses made on combined cytomorphologic and ICC/IHC approach.

RESULTS

Of 71 cases, 32, 10 and 29 had histopathologic, cell block and clinico-radiologic correlation respectively with 55 metastatic adenocarcinomas (MAC), 13 HCCs and one case each of hepatic adenoma (HA), cirrhotic nodule (CN) and intrahepatic cholangiocarcinoma (CC). Cytoplasmic positivity of HepPar-1 and glypican-3 were noted in 11/13 and 8/13 HCCs respectively; while only 3/13 and 1/13 HCCs revealed cytoplasmic positivity for arginase-1 and TTF-1 respectively. Benign hepatic lesions were negative for glypican-3 and TTF-1, but expressed both arginase-1and HepPar-1. Twenty-one of 55 MACs and the lone case of CC were positive for CK-19; however, all MACs and CC cases were negative for HepPar-1, arginase-1, glypican-3 and TTF-1. The immune-panel had sensitivity, specificity and diagnostic accuracy of 100%, 88.9% and 90.6%, respectively, for differentiating HCC from its morphologic mimics.

CONCLUSION

Though a meticulous cytologic evaluation in conjunction with clinicoradiologic profile helps in distinguishing HCC from its benign and malignant mimics; an immunopanel of arginase-1, glypican-3, HepPar-1, TTF-1 and CK-19 drastically improves the diagnostic accuracy.

In situ hybridisation for albumin RNA in paediatric liver cancers compared with common immunohistochemical markers

AIMS

In situ hybridisation (ISH) for albumin mRNA is a sensitive marker of primary liver tumours in adults. However, paediatric tumours, such as hepatoblastoma (HB) and fibrolamellar hepatocellular carcinoma (FLC), have not been tested thoroughly and may require ancillary tests to diagnose with confidence. We aim to determine if albumin ISH is useful in the pathological evaluation of these malignancies and to compare it to commonly used immunohistochemical markers HepPar 1 (HEPA) and arginase-1 (ARG).

METHODS

Tissue microarrays of 26 HB and 10 FLC were constructed. Controls included 4 embryonal undifferentiated sarcomas of the liver, 51 neuroblastomas and 64 Wilms tumours. We evaluated a commercially available RNA ISH to detect albumin mRNA. Immunohistochemistry for HEPA and ARG was performed in the usual fashion.

RESULTS

Twenty-six of 26 HB showed positive staining by albumin ISH including 14 fetal, 8 embryonal and 4 mixed variants. All 10 FLC were diffusely positive. The sensitivity and specificity of albumin ISH were 100% for HB and FLC. ARG had 100% sensitivity and specificity for HB (26 of 26 cases) and FLC (9 of 9). HEPA stained 22 of 26 HB (85% sensitivity, 99.2% specificity) and 7 of 9 FLC (78% sensitivity, 99.1% specificity).

CONCLUSION

Albumin RNA ISH is a useful test to determine hepatocytic origin in HB and FLC. ARG was equally sensitive and easy to interpret, while HEPA was inferior to both in HB and FLC.

The significance of arginase-1 expression in the diagnosis of liver cancer: A protocol for a systematic review

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common primary liver cancer. Pathologic distinction between HCC and intrahepatic cholangiocarcinoma (ICC) and metastatic adenocarcinoma can be challenging and sometimes requires immunohistochemical panels. Recently, arginase-1 (ARG-1) has been introduced for differentiation of these tumors.

METHODS

We will search Cochrane Library, PubMed, Embase, China National Knowledge Infrastructure through August 1, 2019, comprehensive collection studies about the diagnostic value of ARG-1 for HCC. Two reviewers will screen literature according to the inclusion and exclusion criteria, extract data, and assess the quality of included studies. Review Manager 5.3 and STATA 15.0 will be used to conduct the meta-analysis.

RESULTS

The review will provide a high-quality synthesis of current evidence of the diagnostic value of liver cancer. The results will be published in a peer-reviewed journal.

CONCLUSION

We hope that the results of this study will provide significant evidence to assess the value of ARG-1 in differential diagnosis of HCC, ICC, and metastatic carcinoma of liver.

Well differentiated arginase-1 negative hepatocellular carcinoma

Background

The diagnosis of hepatocellular carcinoma (HCC) is dependent on the histologic and immunohistochemical analysis of biopsy and resection specimens. The distinction of HCC from metastatic neoplasms is pertinent for treatment and prognostic purposes. Arginase-1 (Arg-1), a marker of hepatocellular differentiation, has shown superior sensitivity and specificity when compared to other immunohistochemical markers of detection of HCC such as hepatocyte paraffin antigen (HepPar-1). Studies have shown that poorly differentiated HCC can lose arginase expression, however well differentiated HCC are rarely ever arginase negative.

Methods

In this study Arg-1 expression was detected using immunohistochemical staining on tissue specimens from 40 confirmed cases of well differentiated HCC specimens using a highly specific monoclonal antibody for Arg-1. Specificity of the Arg-1 antibody was evaluated by immunostaining of 24 non-HCC tumors in the liver and 200 non-liver neoplasms using paraffin block and tissue micro-array (TMA) based immunohistochemistry.

Results

Four well differentiated HCC cases were found to be completely negative for Arg-1 and similarly all 224 non-HCC tumors did not express Arg-1. The arginase negative well differentiated tumors were positive for other hepatocellular markers such as HepPar-1 and polyclonal carcinoembryonic antigen (pCEA). Of the four tumors, only one recurred at 28 months. All patients are currently stable with a mean survival of 43 months.

Conclusions

Arg-1 negative well differentiated HCC can be a clinical dilemma which can lead to misdiagnosis. Confirmation with other hepatocellular markers such as HepPar1 and pCEA is essential in making the correct diagnosis. The clinicopathologic outcomes of arginase negative well differentiated HCC has been poorly characterized, thus our findings are of utmost importance in understanding the clinical behavior of these tumors. This may have a potential role in understanding the mechanism of the use of targeted therapy in HCC tumors.

Cutaneous metastasis of hepatocellular carcinoma following liver transplantation

Cutaneous metastases from hepatocellular carcinoma (HCC) are extremely rare and can represent a sign of an underlying malignancy or relapse/progression from an existing tumor. We report a case of a cutaneous metastasis arising in a patient with metastatic HCC following orthotopic liver transplantation. Diagnosis is a multistep process as cutaneous HCC metastases must be differentiated from primary cutaneous malignancies as well as other cutaneous metastases. Making this even more challenging, HCC metastases have heterogeneous clinical and histologic appearances. Therefore, the use of immunohistochemical stains, including hepatocyte paraffin-1, arginase-1, and glypican-3, and correlation with the clinical context are essential for a correct diagnosis.

Elevated levels of circulating ITIH4 are associated with hepatocellular carcinoma with nonalcoholic fatty liver disease: from pig model to human study

BACKGROUND

Noninvasive biomarkers are urgently needed for optimal management of nonalcoholic fatty liver disease (NAFLD) for the prevention of disease progression into nonalcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC). In order to identify the biomarkers, we generated the swine hepatocellular carcinoma (HCC) model associated with NAFLD and performed serum proteomics on the model.

METHODS

Microminipigs were fed a high-fat diet to induce NAFLD and a normal diet as the control. To induce HCC, diethylnitrosamine was intraperitoneally administered. Biopsied liver samples were histopathologically analyzed every 12 weeks. Serum proteins were separated by blue native two-dimensional gel electrophoresis and proteins of interest were subsequently identified by MALDI-TOF MS/MS. Human serum samples were analyzed to validate the candidate protein using antibody-mediated characterization.

RESULTS

In the NAFLD pigs, hepatic histology of nonalcoholic steatohepatitis (NASH) was observed at 36 weeks, and HCC developed at 60 weeks. Among serum proteins identified with MALDI-TOF MS/MS, serum inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4), an acute response protein which is secreted primarily by liver, was identified as the most characteristic protein corresponding with NAFLD progression and HCC development in the NAFLD pigs. With immunoassay, serum ITIH4 levels in the NAFLD pigs were chronologically increased in comparison with those in control animal. Furthermore, immunohistochemistry showed ITIH4 expression in hepatocytes also increased in both the cancer lesions and parenchyma as NAFLD progressed. Human study is also consistent with this observation because serum ITIH4 levels were significantly higher in HCC-NAFLD patients than in the simple steatosis, NASH, and virus-related HCC patients. Of note, HCC-NAFLD patients who had higher serum ITIH4 levels exhibited poorer prognosis after hepatectomy.

CONCLUSIONS

We established an HCC pig model associated with NAFLD. Serum proteomics on the swine HCC with NAFLD model implicated ITIH4 as a non-invasive biomarker reflecting NAFLD progression as well as subsequent HCC development. Most importantly, the results in the swine study have been validated in human cohort studies. Dissecting speciation of serum ITIH4 promises to have clinical utility in monitoring the disease.

Histopathological characteristics of needle core biopsy and surgical specimens from patients with solitary hepatocellular carcinoma or intrahepatic cholangiocarcinoma

BACKGROUND

Pathological manifestations of hepatic tumours are often associated with prognosis. Although surgical specimens (SS) can provide more information, currently, pre-treatment needle core biopsy (NCB) is increasingly showing important value in understanding the nature of liver tumors and even in diagnosis and treatment decisions. However, the concordance of the clinicopathological characteristics and immunohistochemical (IHC) staining between NCB and SS from patients with hepatic tumours were less concerned.

AIM

To introduce a more accurate method for interpreting the IHC staining results in order to improve the diagnostic value of hepatic malignancy in NCB samples.

METHOD

A total of 208 patients who underwent both preoperative NCB and surgical resection for hepatocellular carcinoma (HCC) or intrahepatic cholangiocarcinoma (ICC) between 2008 and 2015 were enrolled in this study. The expression of CK19, GPC3, and HepPar1 were detected by IHC staining. Clinicopathological, NCB, and surgical data were collected and analysed using χ² and kappa statistics.

RESULTS

Morphologically, the presence of compact tumour nests or a cord-like structure in NCB was considered the primary cause of misdiagnosis of HCC from ICC. The kappa statistic showed a moderate agreement in histomorphology (k = 0.504) and histological grade (k = 0.488) between NCB and SS of the tumours. A 4-tier (+++, ++, +, and -) scoring scheme that emphasized the focal neoplastic cell immunoreactivity of tumour cells revealed perfect concordance of CK19, GPC3 and HepPar1 between NCB and SS (k = 0.717; k = 0.768; k = 0.633). Furthermore, with the aid of a binary classification derived from the 4-tier score, a high concordance was achieved in interpreting the IHC staining of the three markers between NCB and final SS (k = 0.931; k = 0.907; k = 0.803), increasing the accuracy of NCB diagnosis C (k = 0.987; area under the curve = 0.997, 95%CI: 0.990-1.000; P < 0.001).

CONCLUSION

These findings imply that reasonable interpretation of IHC results in NCB is vital for improving the accuracy of tumour diagnosis. The simplified binary classification provides an easy and applicable approach.

Prognostic Implications of Arginase and Cytokeratin 19 Expression in Hepatocellular Carcinoma After Curative Hepatectomy: Correlation With Recurrence-Free Survival

BACKGROUND

The prognostic value of arginase expression in hepatocellular carcinoma (HCC) has been evaluated previously. However, no clear distinction exists yet on the role of arginase-1 as a predictor of recurrence in HCC. Cytokeratin 19 (CK19), a cholangiocytic marker, is occasionally expressed in HCC, but the combination of arginase-1 and CK19 expression has never been evaluated. The aim of the study was to investigate the usefulness of arginase-1 and CK19 expression alone and in combination for prognosticating HCC tumor recurrence after surgical resection.

METHODS

Tissue sections from 112 HCCs were immunostained using an automated method and the mouse monoclonal arginase-1 and mouse monoclonal CK19 antibodies. The clinicopathologic variables, including alpha-fetoprotein levels, viral hepatitis, cirrhosis, tumor size, grade and number, vascular invasion, tumor-node-metastasis (TNM) stage, and tumor recurrence and survival, were obtained from each patient's medical records. The variables were assessed for correlation with the immunochemical results. Comparisons of recurrence-free and overall survival were performed using univariate and multivariate regression analyses. A P-value of ≤ 0.05 was considered statistically significant.

RESULTS

High arginase-1 expression was detected in the HCCs of 93 patients (83%), whereas CK19 was positive in the HCCs of only 19 patients (17%). In the univariate analyses, CK19 positivity in HCC was associated with decreased recurrence-free survival compared with CK19-negative HCC (P = 0.0002). Arginase-1 expression was associated with decreased recurrence-free survival when patients were stratified over advanced TNM stage and presence of vascular invasion. The combination of arginase-1 and CK19 expression was a better predictor of decreased recurrence-free survival (P = 0.00008). Arginase-1/CK19 expressions when combined with multiple tumors, TNM stage and vascular invasion were also associated with decreased recurrence-free survival. In the multivariate analysis, tumor grade, CK19 and arginase-1/CK19 expressions were identified as independent prognostic indicators for decreased recurrence-free survival.

CONCLUSION

Arginase-1 and CK19 combination immunoreactivity is a potential biomarker of adverse prognosis in HCC, correlating with the presence of multiple tumors, vascular invasion and advanced stage.

Subclassification and Detection of New Markers for the Discrimination of Primary Liver Tumors by Gene Expression Analysis Using Oligonucleotide Arrays

Background/Aims

The failure to correctly differentiate between intrahepatic cholangiocarcinoma (CC) and hepatocellular carcinoma (HCC) is a significant clinical problem, particularly in terms of the different treatment goals for both cancers. In this study a specific gene expression profile to discriminate these two subgroups of liver cancer was established and potential diagnostic markers for clinical use were analyzed.

Methods

To evaluate the gene expression profiles of HCC and intrahepatic CC, Oligonucleotide arrays (AffymetrixU133A) were used. Overexpressed genes were checked for their potential use as new markers for discrimination and their expression values were validated by reverse transcription polymerase chain reaction and immunohistochemistry analyses.

Results

695 genes/expressed sequence tags (ESTs) in HCC (245 up-/450 down-regulated) and 552 genes/ESTs in CC (221 up-/331 down-regulated) were significantly dysregulated (p＜0.05, fold change >2, ≥70%). Using a supervised learning method, and one-way analysis of variance a specific 270-gene expression profile that enabled rapid, reproducible differentiation between both tumors and nonmalignant liver tissues was established. A panel of 12 genes (e.g., HSP90β, ERG1, GPC3, TKT, ACLY, and NME1 for HCC; SPT2, T4S3, CNX43, TTD1, HBD01 for CC) were detected and partly described for the first time as potential discrimination markers.

Conclusions

A specific gene expression profile for discrimination of primary liver cancer was identified and potential marker genes with feasible clinical impact were described.

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.

The Oncogenic Role of ARG1 in Progression and Metastasis of Hepatocellular Carcinoma

ARG1, which encodes Arginase1, is expressed in the liver cytoplasm and plays a major role in the hepatic urea cycle. The past research works shed light on the fact that ARG1 participates in anti-inflammation, tumor immunity, and immunosuppression-related diseases. Nevertheless, the concrete role and clinical significance of ARG1 in the progression of hepatocellular carcinoma (HCC) remain unclear. Herein, we aimed at examining the expression and clinicopathological significance of ARG1 in HCC, together with determining the effect of ARG1 on the progression and metastasis of HCC. In the current study, evaluation of the expression of ARG1 and clinicopathological significance of ARG1 was carried out in the human HCC tissues microarray, and the ARG1 overexpression vector and shRNA-ARG1 plasmids were constructed for the assessment of the concrete effect of ARG1 on cellular behaviors of Huh7 cells. As our data revealed, ARG1 was significantly downregulated in HCC, and the higher expression of ARG1 was positively correlated with more aggressive tumor growth, size, ALT, and GGT level. Significantly, we found that the high expression of ARG1 was correlated with poor DFS of HCC patients. Besides, in vitro study revealed that overexpression of ARG1 could enhance arginase activity, cell viability, migration, and invasion of Huh7 cells, and loss-of-function of ARG1 by shRNA interference could inhibit these cellular behaviors. Additionally, overexpression of ARG1 led to a significant increase in the expression of Vimentin, N-cadherin, and β-catenin both at protein and mRNA levels, which promotes the EMT process. On the other hand, these proteins' expression was significantly downregulated in ARG1 silenced Huh7 cells. Besides, the level of E-cadherin protein was upregulated in ARG1 knocked down cells. In conclusion, ARG1 might play a pivotal role as an oncogene in the progression of HCC through promoting the EMT process.

Primary Liver Cancers-Part 1: Histopathology, Differential Diagnoses, and Risk Stratification

Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) are the 2 most common primary malignant liver tumors, with hepatocellular and bile ductular differentiation, respectively. This article reviews the key histopathological findings of these 2 primary liver cancers and includes a review of the role of ancillary testing for differential diagnosis, risk stratification according to the American Joint Committee on Cancer (AJCC) staging recommendation, and a review of precancerous lesions. A literature review was conducted to identify articles with information relevant to precancerous precursors, current histopathological classification, ancillary testing, and risk stratification of primary malignant liver tumors. The histomorphology of normal liver, preinvasive precursors, primary malignancies, and morphological variants, and the utilization of ancillary tests for the pathological diagnosis are described. Dysplastic nodules are the preinvasive precursors of HCC, and intraductal papillary neoplasms of bile ducts and biliary intraepithelial neoplasia are the preinvasive precursors of CC. Benign liver nodules including focal nodular hyperplasia and adenomas are included in this review, since some forms of adenomas progress to HCC and often they have to be differentiated from well-differentiated HCC. A number of morphological variants of HCC have been described in the literature, and it is necessary to be aware of them in order to render the correct diagnosis. Risk stratification is still dependent on the AJCC staging system. The diagnosis of primary liver carcinomas is usually straightforward. Application of the appropriate ancillary studies aids in the differential diagnosis of difficult cases. The understanding of the carcinogenesis of these malignancies has improved with the standardization of the pathological classification of preinvasive precursors and studies of the molecular pathogenesis. Risk stratification still depends on pathological staging.

Update on Ancillary Testing in the Evaluation of High-Grade Liver Tumors

Tissue diagnosis is the gold standard for mass lesions of the liver, but needle core biopsies may sometimes prove challenging. Presented here is a review of a panel of immunohistochemical stains, including hepatocyte in paraffin 1, arginase-1, polyclonal carcinoembryonic antigen, CD10, bile salt export pump, glypican-3, as well as in situ hybridization for albumin RNA, to establish hepatocellular origin in cases in which hepatocellular carcinoma is suspected but the sample is limited or the morphology is challenging, as it may be with cases of scirrhous, fibrolamellar carcinoma, intrahepatic cholangiocarcinoma, and combined hepatocellular-cholangiocarcinoma.

Clear cell hepatocellular carcinoma: origin, metabolic traits and fate of glycogenotic clear and ground glass cells

Clear cell hepatocellular carcinoma (CCHCC) has hitherto been considered an uncommon, highly differentiated variant of hepatocellular carcinoma (HCC) with a relatively favorable prognosis. CCHCC is composed of mixtures of clear and/or acidophilic ground glass hepatocytes with excessive glycogen and/or fat and shares histology, clinical features and etiology with common HCCs. Studies in animal models of chemical, hormonal and viral hepatocarcinogenesis and observations in patients with chronic liver diseases prone to develop HCC have shown that the majority of HCCs are preceded by, or associated with, focal or diffuse excessive storage of glycogen (glycogenosis) which later may be replaced by fat (lipidosis/steatosis). In ground glass cells, the glycogenosis is accompanied by proliferation of the smooth endoplasmic reticulum, which is closely related to glycogen particles and frequently harbors the hepatitis B surface antigen (HBsAg). From the findings in animal models a sequence of changes has been established, commencing with preneoplastic glycogenotic liver lesions, often containing ground glass cells, and progressing to glycogen-poor neoplasms via various intermediate stages, including glycogenotic/lipidotic clear cell foci, clear cell hepatocellular adenomas (CCHCA) rich in glycogen and/or fat, and CCHCC. A similar process seems to take place in humans, with clear cells frequently persisting in CCHCC and steatohepatitic HCC, which presumably represent intermediate stages in the development rather than particular variants of HCC. During the progression of the preneoplastic lesions, the clear and ground glass cells transform into cells characteristic of common HCC. The sequential cellular changes are associated with metabolic aberrations, which start with an activation of the insulin signaling cascade resulting in pre-neoplastic hepatic glycogenosis. The molecular and metabolic changes underlying the glycogenosis/lipidosis are apparently responsible for the dramatic metabolic shift from gluconeogenesis to the pentose phosphate pathway and Warburg-type glycolysis, which provide precursors and energy for an ever increasing cell proliferation during progression.

Immunohistochemistry, carcinomas of unknown primary, and incidence rates

Pathologists use immunohistochemistry is their day-to-day practices to assist in distinguishing site of origin of metastatic carcinomas. Here, the work-up is discussed neuroendocrine carcinomas, squamous cell carcinomas and adenocarcinomas with particular attention to tumor incident rates and predictive values of the best-performing immunohistochemical markers.

Practical Immunohistochemistry in Neoplastic Pathology of the Gastrointestinal Tract, Liver, Biliary Tract, and Pancreas

CONTEXT

- Immunomarkers with diagnostic, therapeutic, or prognostic values have been increasingly used to maximize the benefits of clinical management of patients with neoplastic diseases of the gastrointestinal tract, liver, biliary tract, and pancreas.

OBJECTIVES

- To review the characteristics of immunomarkers that are commonly used in surgical pathology practice for neoplasms of the gastrointestinal tract, liver, biliary tract, and pancreas, and to summarize the clinical usefulness of immunomarkers that have been discovered in recent years in these fields.

DATA SOURCES

- Data sources include literature review, authors' research data, and personal practice experience.

CONCLUSIONS

- Immunohistochemistry is an indispensable tool for the accurate diagnosis of neoplastic diseases of the gastrointestinal tract, liver, biliary tract, and pancreas. Useful immunomarkers are available to help distinguish malignant neoplasms from benign conditions, determine organ origins, and subclassify neoplasms that are morphologically and biologically heterogeneous. Specific immunomarkers are also available to help guide patient treatment and assess disease aggressiveness, which are keys to the success of personalized medicine. Pathologists will continue to play a critical role in the discovery, validation, and application of new biomarkers, which will ultimately improve patient care.

Fetal-type gastrointestinal adenocarcinoma: a morphologically distinct entity with unfavourable prognosis

AIMS

This multi-institutional study and a re-evaluation of the TCGA cohort explores the morphological spectrum, genetics and outcome of GI (gastrointestinal) hepatoid tumours, tumours expressing alpha-fetoprotein (AFP) and fetal-type (FT) GI adenocarcinomas.

METHODS

44 tumours with evidence of hepatocellular differentiation were evaluated for morphology as well as by immunohistochemistry for AFP, HepPar1, glypican-3 and arginase-1 and by in situ hybridisation for albumin. Three categories were defined: type I (hepatoid: morphological evidence of hepatocellular differentiation), type II (FT GI adenocarcinoma: tubular profiles and subnuclear vacuolisation, resembling fetal intestine) and type III: positive for at least two hepatocyte-specific markers but lacking morphological evidence of hepatocellular differentiation. GI adenocarcinomas in the TCGA cohort were also evaluated (n=829).

RESULTS

18 cases were classified as type I, 19 as FT GI adenocarcinomas and 7 as type III (resembling conventional gastrointestinal carcinomas). Serum AFP was elevated in 92% of cases. 93% of tumours were positive for glypican-3, 90% for albumin and 89% for AFP. Arginase-1 was restricted to 35% of type 1 tumours. TCGA gastric tumours with elevated AFP expression showed morphological features of FT GI adenocarcinoma (70%) and were exclusively MSI stable. TCGA gastric adenocarcinomas with high AFP expression showed inferior survival on univariate and multivariate analysis.

CONCLUSIONS

FT GI adenocarcinomas show a distinctive morphological and immunohistochemical profile. Gastric adenocarcinomas with elevated expression of AFP morphologically resemble FT GI adenocarcinomas, demonstrate aggressive behaviour, independent of grade and stage, and a distinct genetic profile.

Identification of proteasome subunit alpha type-1 as a novel biomarker in HBV-associated hepatocellular carcinoma tissue interstitial fluid by proteomic analysis

Differentially expressed proteins between HCC TIF and normal interstitial fluid of adjacent nontumor tissues were identified through comparative proteomics approach. Then, two-dimensional gel electrophoresis (2-DE), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), In-Cell Western technique, and reverse transcription-polymerase chain reaction (RT-PCR) were used to verify differentially expressed proteins. As a result, through 2-DE, 69 spots were roughly recognized as differentially expressed protein spots, while 44 proteins were identified as differentially expressed spots through MALDI-TOF-MS. Of the identified differential protein spots, 31 were significant according to the bioinformatics analysis results. Proteasome subunit alpha type-1 (PSMA1) expression was down-regulated in HCC TIF. Thus, PSMA1 is considered as a potential biomarker for HBV-associated hepatocellular carcinoma.

Tissue Biomarkers in Hepatocellular Tumors: Which, When, and How

Few tissue markers are currently available to pathologists in the study of hepatocellular tumors. These markers should be used carefully taking into consideration not only morphology but also, and sometimes even more important, the clinical setting where the lesion to be diagnosed had developed. Glypican-3, heat shock protein 70, and glutamine synthetase (GS) are markers currently used, as a single panel, to discriminate the nature of a <2 cm hepatocellular lesion lacking radiological features of hepatocellular carcinoma (HCC) detected in a cirrhotic patient under surveillance. Their use, which can be improved by clathrin heavy chain, is mostly requested on liver biopsy. Hepatocyte paraffin 1, arginase-1, polyclonal carcinoembryonic antigen, CD10, and bile salt export pump are tissue markers used to confirm, at histology, the diagnosis of HCC made by imaging before enrollment for phase III studies on novel anti-HCC drugs. In this setting, pathologists are usually requested a conclusive diagnosis on a liver biopsy of a poorly differentiated, necrotic, enriched in stem-phenotype, carcinoma. Liver fatty acid-binding protein, serum amyloid A, C-reactive protein, prostaglandin D2 synthetase, GS, and β-catenin can be used either on biopsy or surgical specimen to classify hepatocellular adenoma into hepatocyte nuclear factor (HNF-1α) inactivated (steatotic), inflammatory, with dysregulation of sonic hedgehog and prostaglandin pathways, β-catenin mutated, and unclassified.

Expression of Markers of Hepatocellular Differentiation in Pancreatic Acinar Cell Neoplasms: A Potential Diagnostic Pitfall

OBJECTIVES

Pancreatic acinar cell carcinoma (ACC) is a rare tumor that frequently metastasizes to the liver and may present a diagnostic challenge due to its morphologic similarity to hepatocellular carcinoma. We investigated α-fetoprotein (AFP), hepatocyte paraffin antigen 1 (HepPar 1), glypican 3, arginase 1, and albumin messenger RNA (mRNA) in situ hybridization (ISH) in pancreatic neoplasms with ACC differentiation to assess their diagnostic value.

METHODS

AFP, HepPar 1, glypican 3, and arginase 1 immunohistochemical staining was performed on 28 ACCs using a tissue microarray. Albumin mRNA ISH was performed on full-faced sections.

RESULTS

Fifteen tumors were positive for at least one marker. Glypican 3 was positive in seven of 28, AFP in five 28, and albumin mRNA ISH in five of 20. None expressed arginase 1.

CONCLUSIONS

Hepatocellular differentiation markers, including albumin mRNA ISH, may be positive in ACC, but arginase 1 appears to be uniformly negative. Thus, its use may improve the accuracy in distinguishing these neoplasms from hepatocellular carcinoma. If ACC diagnosis is considered, acinar differentiation can be reliably demonstrated by trypsin/chymotrypsin.

Meta-analysis of gene expression profiles identifies differential biomarkers for hepatocellular carcinoma and cholangiocarcinoma

Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) are the members of hepatobiliary diseases. Both types of cancer often exert high levels of similarity in terms of phenotypic characteristics, thus leading to difficulties in HCC and CCA differential diagnoses. In this study, a transcriptome meta-analysis was performed on HCC and CCA microarray data to identify differential transcriptome networks and potential biomarkers for HCC and CCA. Raw data from nine gene expression profiling datasets, consisting of 1,185 samples in total, were methodologically compiled and analyzed. To evaluate differentially expressed (DE) genes in HCC and CCA, the levels of gene expression were compared between cancer and its normal counterparts (i.e., HCC versus normal liver and CCA versus normal bile duct) using t test (P < 0.05) and k-fold validation. A total of 226 DE genes were specific to HCC, 249 DE genes specific to CCA, and 41 DE genes in both HCC and CCA. Gene ontology and pathway enrichment analyses revealed different patterns between functional transcriptome networks of HCC and CCA. Cell cycle and glycolysis/gluconeogenesis pathways were exclusively dysregulated in HCC whereas complement and coagulation cascades as well as glycine, serine, and threonine metabolism were prodominantly differentially expressed in CCA. Our meta-analysis revealed distinct dysregulation in transcriptome networks between HCC and CCA. Certain genes in these networks were discussed in the context of HCC and CCA transition, unique characteristics of HCC and CCA, and their potentials as HCC and CCA differential biomarkers.

Comparison of 5 Immunohistochemical Markers of Hepatocellular Differentiation for the Diagnosis of Hepatocellular Carcinoma

CONTEXT

Several immunohistochemical markers are available to establish the diagnosis of hepatocellular carcinoma. Judicious selection is essential to achieve a reliable diagnosis in limited tissue provided by liver biopsy.

OBJECTIVE

To compare the efficacy of 5 hepatocellular markers for the diagnosis of hepatocellular carcinoma across various levels of differentiations.

DESIGN

Immunohistochemistry for hepatocyte paraffin antigen 1 (Hep Par 1), polyclonal carcinoembryonic antigen (CEA), glypican-3, arginase-1, and bile salt export pump transporter was performed in 79 hepatocellular carcinomas, yielding 93 observations (13 well-differentiated [14%], 41 moderately differentiated [44%], and 39 poorly differentiated [42%] tumors).

RESULTS

Arginase-1 and Hep Par 1 had the highest sensitivity for well-differentiated hepatocellular carcinoma, whereas arginase-1 and glypican-3 had the highest sensitivity for poorly differentiated hepatocellular carcinoma. When staining of more than 50% of the tumor was considered a positive result, arginase-1 remained the most sensitive marker for all differentiations, whereas sensitivity for Hep Par 1 in poorly differentiated hepatocellular carcinoma dropped to 30% and that of glypican-3 in well-differentiated hepatocellular carcinoma was 15%. The addition of Hep Par 1 and/or polyclonal CEA to arginase-1 did not lead to an increase in sensitivity for any differentiation. The combined use of arginase-1 and glypican-3 yielded 100% sensitivity for poorly differentiated hepatocellular carcinoma.

CONCLUSION

Arginase-1 was the most sensitive marker in all differentiations of hepatocellular carcinoma. Glypican-3 had high sensitivity for poorly differentiated cases and its combined use with arginase-1 enabled identification of nearly all cases of poorly differentiated hepatocellular carcinoma. Although bile salt export pump transporter has good overall sensitivity, it has a limited role in establishing hepatocellular differentiation when added to a panel of arginase-1 with either glypican-3 or Hep Par 1.

The Applicability of a Human Immunohistochemical Panel to Mouse Models of Hepatocellular Neoplasia

Various immunohistochemical panels are used as aids to distinguish between primary hepatocellular malignancies and metastatic tumors and between benign lesions and carcinomas. We compared the immunohistochemical spectrum of hepatocellular lesions in mice with that of human hepatocellular carcinoma (HCC). Specifically, we compared the staining parameters of 128 murine foci of cellular alteration (FCA) and tumors (adenoma and HCC) from archival tissue blocks of 3 transgenic mouse models (LFABP-cyclin D1, Alb1-TGFβ1, and LFABP-cyclin D1 × Alb1-TGFβ1) with those of archival human HCC (n = 5). Antibodies were chosen according to their published performance and characterization in human hepatocellular tumor diagnosis and included: arginase 1 (Arg1), β-catenin, glutamine synthetase (GS), glypican 3, hepatocyte paraffin 1 (HepPar1), and cytokeratin 19 (CK19). GS was the single best immunostain for identifying hepatocellular tumors in mice, with 100% positive staining. Data showed a trend toward loss of normal function (staining) with Arg1, with a higher percentage of positive staining in FCA than in adenomas and HCC. All FCA lacked murine β-catenin nuclear translocation, which was present in 2 of the 7 adenomas and 22 of the 96 HCC tested. HepPar1 staining was lower than anticipated, except in trabecular HCC (16 of 22 samples were positive). Glyp3 stained very lightly, and only scattered CK19-positive cells were noted (4 of 44 cases of mouse trabecular HCC). Thus, GS appears to be the most useful marker for identifying neoplasia in the transgenic mouse models we tested and should be included in immunohistochemistry assessing hepatocellular neoplasia development.

Diagnostic Value of Arginase-1 and Glypican-3 in Differential Diagnosis of Hepatocellular Carcinoma, Cholangiocarcinoma and Metastatic Carcinoma of Liver

BACKGROUND

Hepatocellular carcinoma is the most common primary liver cancer. Pathologic distinction between Hepatocellular Carcinoma (HCC) and adenocarcinoma (Cholangiocarcinoma (CC) and Metastatic Adenocarcinoma (MA)) can be challenging and sometimes requires immunohistochemical panels. Recently, Arginase-1 (ARG-1) and Glypican-3 (GPC-3) have been introduced for differentiation of these tumors.

OBJECTIVES

The aim of this study was to determine the diagnostic accuracy of ARG-1 and GLP-3 in differential diagnosis of liver tumors.

PATIENTS AND METHODS

Eighty-nine formalin-fixed paraffin-embedded tissue blocks including 43 cases of documented HCCs, 19 cases of documented CC, and 27 cases of MA involving the liver (15 colon, 5 stomach, 3 pancreas, 2 gallbladder, 1 duodenum and 1 ampulla of vater) were evaluated for immunohistochemical expression of ARG-1 and GPC-3.

RESULTS

Arginase-1 and GPC-3 demonstrated diffuse staining, as reactivity in > 97% of HCCs, whereas only one (5.3%) and 2 (10.5%) of 19 CC cases show positive staining for GPC-3 and ARG-1, respectively. The expression of both markers in MA showed 6 (22.2%) for ARG-1 and 3 (11.1%) for GPC-3, especially with colorectal origin. Our findings showed a statistically significant difference between ARG-1 and GPC-3 expression in HCC, CC and MA.

CONCLUSIONS

The findings of this study reveal that both ARG-1 and GPC-3 are helpful IHC markers to separate HCC from CC and MA. Furthermore, ARG-1 shows 100% sensitivity and 82.6% specificity for the diagnosis of HCC whereas GPC-3 demonstrated 97.7% sensitivity and 91.3% specificity for the diagnosis of this tumor.

Biphenotypic (hepatobiliary) primary liver carcinomas: the work in progress

Recent WHO classification for combined hepatocellular-cholangiocarcinoma and recognized stem cell subtypes has increased attention to such tumors; however, the resulting burst of reporting and research indicates that this classification, while provocative, is incomplete for description of the full array of primary liver carcinomas with biphenotypic (hepatobiliary) differentiation. We review the history of such lesions and consider the wider array of such tumors previously described. Mixed hepatobiliary phenotypes and immunophenotypes are found in individual tumors at the tissue level - with architectural and cytologic features supportive of both differentiation states - and at the cellular level, with individual cells that display cytology of one cell type, but immunophenotypically showing mixed expression. Pathobiologic and clinical questions to be answered by future research are suggested.

Multidisciplinary perspective of hepatocellular carcinoma: A Pacific Northwest experience

Hepatocellular carcinoma (HCC) is the most rapidly increasing type of cancer in the United States. HCC is a highly malignant cancer, accounting for at least 14000 deaths in the United States annually, and it ranks third as a cause of cancer mortality in men. One major difficulty is that most patients with HCC are diagnosed when the disease is already at an advanced stage, and the cancer cannot be surgically removed. Furthermore, because almost all patients have cirrhosis, neither chemotherapy nor major resections are well tolerated. Clearly there is need of a multidisciplinary approach for the management of HCC. For example, there is a need for better understanding of the fundamental etiologic mechanisms that are involved in hepatocarcinogenesis, which could lead to the development of successful preventive and therapeutic modalities. It is also essential to define the cellular and molecular bases for malignant transformation of hepatocytes. Such knowledge would: (1) greatly facilitate the identification of patients at risk; (2) prompt efforts to decrease risk factors; and (3) improve surveillance and early diagnosis through diagnostic imaging modalities. Possible benefits extend also to the clinical management of this disease. Because there are many factors involved in pathogenesis of HCC, this paper reviews a multidisciplinary perspective of recent advances in basic and clinical understanding of HCC that include: molecular hepatocarcinogenesis, non-invasive diagnostics modalities, diagnostic pathology, surgical modality, transplantation, local therapy and oncological/target therapeutics.