Arginase-1: a novel immunohistochemical marker of hepatocellular differentiation in fine needle aspiration cytology

Patient with a novel syndrome with multiple benign hepatic lesions and extrahepatic neoplasms

Simultaneous occurrence of benign hepatic lesions of different types is a sporadic phenomenon. To the best of our knowledge, we report the first clinical case of a syndrome with simultaneous manifestations of three different entities of benign liver tumors (hepatocellular adenoma, focal nodular hyperplasia and hemangioma) with a novel mutation detected in the liver adenoma and in the presence of a number of further extrahepatic organ neoplasms. Furthermore, we describe for the first time the presence of liver epithelial cells of hepatocytic phenotype expressing cytokeratin 7 (CK7) at the border of the adenoma. These findings may be important for explaining pathogenesis of benign as well as malignant tumors based on genetic and histopathological features.

Early hepatic proteomic signatures reveal metabolic changes in high-fat-induced obesity in rats

The prevalence of diet-related obesity is increasing dramatically worldwide, making it important to understand the associated metabolic alterations in the liver. It is well known that obesity is a multifactorial condition that is the result of complex integration between many gene expressions and dietary factors. Obesity alone or in conjunction with other chronic diseases such as diabetes and insulin resistance causes many health problems and is considered a major risk factor for developing non-alcoholic steatohepatitis (NASH) and cirrhosis. In this study, we aimed to understand the molecular mechanisms underlying early hepatic changes in the pathophysiology of high-fat diet (HFD)-induced abdominal obesity in rats. Hepatic protein profiles of normal diet and HFD-induced obesity for 24 weeks were analysed using two-dimensional differential gel electrophoresis (DIGE) and protein identification by MS. Fifty-two proteins were identified by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF), and computer-assisted DIGE image software analysis showed that eighteen major proteins were significantly differentially expressed between comparable groups, with 2·0–4·0-fold change/more (P < 0·01). These proteins are regulated in response to a HFD, and differentially expressed proteins are involved in key metabolic pathways such as lipid metabolism, energy metabolism, detoxification, urea cycle and hepatic Ca homoeostasis. In addition, Western blot and immunohistochemistry of liver-specific arginase-1 (Arg-1) showed significant increased expression in the liver of high-fat-fed rats (P < 0·01). Further, Arg-1 expression was correlated with NASH patients with obesity-related fibrosis (F0–F4). It is concluded that high-fat content may affect changes in liver pathways and may be a therapeutic target for obesity-related liver disease. Arg-1 expressions may be a potential pathological marker for assessing the progression of the disease.

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.

PPIH gene regulation system and its prognostic significance in hepatocellular carcinoma: a comprehensive analysis

BACKGROUND

Peptidyl-prolyl isomerase H (PPIH) is a member of the cyclophilin protein family, which functions as a molecular chaperone and is involved in the splicing of pre-mRNA. According to reports, the malignant progression of HCC related to hepatitis B virus (HBV) is tightly associated with RNA-binding proteins. Nevertheless, there is no research on PPIH expression or its function in the occurrence and progression of HCC.

RESULTS

We are the first to reveal that the mRNA and protein levels of Ppih are substantially overexpressed in HCC, as the outcomes show. A significant correlation existed between enriched expression of Ppih within HCC and more advanced, poorly differentiated, and TP53-mutated tumors.

CONCLUSION

These findings, which suggest that Ppih may serve as a predictive biomarker for people with HCC, serve as a starting point for further investigation into the function of Ppih in the progression of carcinogenesis.

METHODS

Accordingly, we utilized clinical samples and bioinformatics analysis to assess Ppih's mRNA, protein expression, and gene regulatory system in HCC. Additionally, Wilcoxon signed-rank testing and logistic regression were utilized to inspect the association between clinicopathological factors and Ppih. Clinical pathological traits linked to overall survival (OS) among HCC patients were examined via TCGA data via Cox regression and the Kaplan-Meier approach. Additionally, via TCGA data collection, gene set enrichment assessment was also conducted.

The Complementary Role of PET to Pathology in Differentiating the Primary Origin of a Malignant Skin Nodule from Liver or Lung

Metastasis from unknown primary is always a challenge because finding the true primary tumor significantly affects subsequent management. We present a case of malignant abdominal wall nodule initially diagnosed as metastasis from hepatocellular carcinoma through excisional biopsy and immunohistochemical (IHC) staining. Dual-tracer positron emission tomography/computed tomography (PET/CT) with 11C-acetate and 18F-FDG, however, showed metabolic findings in favor of metastasis from lung origin, which was finally confirmed by ensuing a lung biopsy with additional IHC stains. This case illustrates the complementary molecular role of PET to pathology, particularly when dual-tracer or multi-tracer PET is used in conjunction with pathology methods for cross referencing and confirmation.

Immunocytochemistry for diagnostic cytopathology-A practical guide

Cytological specimens, which are obtained by minimally invasive methods, are an excellent source of diagnostic material. Sometimes they are the only material available for diagnosis as well as for prognostic/predictive markers. When cytomorphology is not straightforward, ancillary tests may be required for a definitive diagnosis to guide clinical management. Immunocytochemistry (ICC) is the most common and practical ancillary tool used to reach a diagnosis when cytomorphology is equivocal, to differentiate entities with overlapping morphological features, and to determine the cell lineage and the site of origin of a metastatic neoplasm. Numerous immunomarkers are available, and some are expressed in multiple neoplasms. To rule out entities within a differential diagnosis, the use of more than one marker, sometimes panels, is necessary. ICC panels for diagnostic purposes should be customised based on the clinical context and cytomorphology, and the markers should be used judiciously to preserve material for additional tests for targeted therapies in the appropriate setting. This review offers a practical guide for the use of ICC for diagnostic cytopathology, covering the most commonly encountered non-hematolymphoid diagnostic scenarios in various body sites.

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.

A novel multifunctional gold nanorod-mediated and tumor-targeted gene silencing of GPC-3 synergizes photothermal therapy for liver cancer

Tumor-specific targeted delivery is a major obstacle to clinical treatment of hepatocellular carcinoma (HCC). Here we have developed a novel multi-functional nanostructure GAL-GNR-siGPC-3, which consists of Galactose (GAL) as the HCC-targeting moiety, golden nanorods (GNR) as a framework to destroy tumor cells under laser irradiation, and siRNA of Glypican-3 (siGPC-3) which induce specifically gene silence of GPC-3 in HCC. Glypican-3 (GPC-3) gene is highly associated with HCC and is a new potential target for HCC therapy. On the other hand, Gal can specifically bind to the asialoglycoprotein receptor which is highly expressed on membrane of hepatoma cells. GAL and siGPC-3 can induce targeted silencing of GPC-3 gene in hepatoma cells. In vivo and in vitro results showed that GAL-GNR-siGPC-3 could significantly induce downregulation of GPC-3 gene and inhibit the progression of HCC. More notably, GAL-GNR-siGPC-3 could induce both GPC-3 gene silencing and photothermal effects, and the synergistic treatment of tumors was more effective than individual treatments. In summary, GAL-GNR-siGPC-3 achieved a synergistic outcome to the treatment of cancer, which opens up a new approach for the development of clinical therapies for HCC.

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.

Clinicopathological features and prognosis of AFP-producing colorectal cancer: a single-center analysis of 20 cases

Background: High serum levels of alpha-fetoprotein (AFP) are observed in some gastrointestinal cancers. However, primary AFP-producing colorectal cancer (CRC) is extremely rare and causes confusion among clinicians. In this study, we analyzed the clinicopathological features and clinical outcomes of AFP-producing CRC and provide a brief view of this rare carcinoma.

Patients and methods: Twenty patients with AFP-producing CRC were enrolled at the Fudan University Shanghai Cancer Center from 2012 to 2015. Clinical information, including serum AFP and CEA levels, and outcomes were collected. Tumors were divided into three histologic types: the common adenocarcinoma (COM) type, mucinous adenocarcinoma type and hepatoid type (HPT). Immunohistochemical (IHC) staining of GPC3, Hepa-1, SALL4 and Arg-1 was performed. Additionally, mutations of the KRAS, NRAS and BRAF genes were examined. Finally, another 40 stage-matched patients with traditional CRC were enrolled as controls for survival analysis.

Results: AFP-producing CRC was more likely to occur in males (60%) and arose mainly from the ascending (40%) and sigmoid (35%) colon. In addition, the majority of patients with AFP-producing CRC had poor differentiation (50%), advanced local invasion (80%) and lymph node (LN) metastasis (60%). Synchronous distant metastasis was commonly observed (35%). Interestingly, serum AFP levels were closely associated with LN metastasis. Histopathologically, the COM type was the most common pattern. In IHC staining, the HPT pattern was the most distinct due to high positivity rates of GPC3, Hepa-1 and Arg-1. One patient had mismatch repair deficiency, and another had a KRAS mutation. Patients with AFP-producing CRC had worse progression-free and overall survival than patients with traditional CRC.

Conclusion: AFP-producing CRC has unique clinical and histopathological characteristics, showing an aggressive biological behavior and worse prognosis than traditional CRC.

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.

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.

In Silico Analysis Validates Proteomic Findings of Formalin-fixed Paraffin Embedded Cutaneous Squamous Cell Carcinoma Tissue

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) is a common type of skin cancer but there are no comprehensive proteomic studies on this entity.

MATERIALS AND METHODS

We employed liquid chromatography coupled with tandem mass spectrometry (MS/MS) using formalin-fixed paraffin-embedded (FFPE) cSCC material to study the tumor and normal skin tissue proteomes. Ingenuity Pathway Analysis (IPA) was used to interpret the role of altered proteins in cSCC pathophysiology. Results were validated using the Human Protein Atlas and Oncomine database in silico.

RESULTS

Of 1,310 unique proteins identified, expression of an average of 144 and 88 proteins were significantly (p<0.05) increased and decreased, respectively, in the tumor samples compared to their normal counterparts. IPA analysis revealed disruptions in proteins associated with cell proliferation, apoptosis, and migration. In silico analysis confirmed that proteins corresponding to 12 antibodies, and genes corresponding to 18 proteins were differentially expressed between the two categories, validating our proteomic measurements.

CONCLUSION

Label-free MS-based proteomics is useful for analyzing FFPE cSCC tissues.

Immunohistochemical approach for the diagnosis of a liver mass on small biopsy specimens

Well-differentiated hepatocellular carcinoma (HCC) shares overlapping histological features with benign hepatocellular lesions, including hepatocellular adenoma and focal nodular hyperplasia in non-cirrhotic liver, and with high-grade dysplastic nodule in cirrhotic liver. Several metastatic tumors, such as neuroendocrine tumor, renal cell carcinoma, adrenocortical carcinoma, melanoma, and epithelioid angiomyolipoma, can be indistinguishable from HCC on histologic grounds. Since this distinction has important therapeutic implications, judicious use of immunohistochemical markers plays an important role in establishing an accurate diagnosis, especially when limited material of tumor is available on cell block or a small core biopsy. This review describes commonly used immunohistochemical markers used in the diagnosis of HCC, highlighting advantages and disadvantages of each marker, and suggests appropriate immunohistochemical panels for specific clinicopathologic situations.

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.

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.

Application of immunohistochemistry in gastrointestinal and liver neoplasms: new markers and evolving practice

CONTEXT

Diagnosis of primary gastrointestinal and liver neoplasms is usually straightforward. Immunohistochemistry is most helpful to differentiate metastatic carcinomas with morphologic similarity and to resolve tumors of unknown origin. Recently, several new markers highly sensitive and specific for primary liver and gastrointestinal tumors have been discovered. Their potential diagnostic application has not been widely appreciated by general practicing pathologists. In addition, a new trend in immunohistochemistry application has started, focusing on assessing predictive markers (such as human epidermal growth factor receptor 2) and mutation-specific markers (v-raf murine sarcoma viral oncogene homolog B V600E) to directly guide clinical management. Practicing pathologists need to be aware of and prepared for this evolving trend.

OBJECTIVES

To summarize the usefulness of several recently discovered immunohistochemical markers in the study of gastrointestinal and liver tumors; to suggest the most current and effective immunohistochemical panels addressing common diagnostic challenges for these tumors; to share practical experience and useful tips for human epidermal growth factor receptor 2 testing in gastric and gastroesophageal junction adenocarcinoma and v-raf murine sarcoma viral oncogene homolog B V600E immunohistochemistry in colorectal carcinoma.

DATA SOURCES

Sources include literature review, and authors' research data and practice experience. The cases illustrated are selected from the pathology archives of the Geisinger Medical Center (Danville, Pennsylvania).

CONCLUSIONS

Application of immunohistochemistry in gastrointestinal and liver tumors continues to evolve. New tumor-specific markers constantly emerge and help pathologists to further improve diagnostic accuracy. Assessment of predictive and prognostic markers by immunohistochemistry in routine pathologic diagnosis is a new trend and will greatly facilitate the advancement of personalized cancer therapy.

Immunohistochemistry in undifferentiated neoplasm/tumor of uncertain origin

CONTEXT

Immunohistochemistry has become an indispensable ancillary study in the identification and classification of undifferentiated neoplasms/tumors of uncertain origin. The diagnostic accuracy has significantly improved because of the continuous discoveries of tissue-specific biomarkers and the development of effective immunohistochemical panels.

OBJECTIVES

To identify and classify undifferentiated neoplasms/tumors of uncertain origin by immunohistochemistry.

DATA SOURCES

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

CONCLUSIONS

To better guide therapeutic decisions and predict prognostic outcomes, it is crucial to differentiate the specific lineage of an undifferentiated neoplasm. Application of appropriate immunohistochemical panels enables the accurate classification of most undifferentiated neoplasms. Knowing the utilities and pitfalls of each tissue-specific biomarker is essential for avoiding potential diagnostic errors because an absolutely tissue-specific biomarker is exceptionally rare. We review frequently used tissue-specific biomarkers, provide effective panels, and recommend diagnostic algorithms as a standard approach to undifferentiated neoplasms.

Arginase-1 and HepPar-1 expression in fine-needle aspiration specimens of primary lung adenocarcinoma

INTRODUCTION

Arginase-1 is a novel immunohistochemical (IHC) marker for hepatocellular differentiation. The purpose of this study was to evaluate the expression of Arginase-1 and HepPar-1 in lung adenocarcinoma to assess the potential value of these markers for diagnosing metastatic lung tumors, especially to the liver in fine-needle aspiration specimens.

MATERIALS AND METHODS

Forty-four cytology specimens of lung adenocarcinoma, obtained by endobronchial ultrasound-guided fine-needle aspiration were retrospectively reviewed. IHC stains for Arginase-1 and HepPar-1 were performed on formalin-fixed paraffin-embedded cell blocks. Tissue from confirmed hepatocellular carcinoma was used as the positive control. TTF-1 IHC stain was performed in all cases.

RESULTS

All 44 lung adenocarcinoma cases (100%) were negative for Arginase-1, whereas HepPar-1 expression was detected in 3 (7%) of lung adenocarcinomas and negative in 41 (93%). The 3 HepPar-1-positive lung adenocarcinoma cases demonstrated positive TTF-1 IHC stain performed on the same cell block. Although both Arginase-1 and HepPar-1 are useful diagnostic IHC markers to differentiate metastatic lung adenocarcinoma from hepatocellular carcinoma, Arginase-1 IHC stain shows better specificity than HepPar-1 does (Arginase-1 specificity 100% and HepPar-1 specificity 93%).

CONCLUSIONS

Arginase-1 IHC can be used in combination with other markers in the workup of metastatic lung adenocarcinoma, especially to the liver.

Discovery and diagnostic value of a novel oncofetal protein: glypican 3

Glypican 3 is a membrane-bound heparan sulfate proteoglycan, which has recently been identified as a marker for liver cancer and germ cell malignancies. Individuals with loss-of-function mutations for the glypican 3 gene exhibit Simpson-Golabi-Behmel syndrome, a rare X-linked overgrowth disorder. Expression of glypican 3 mRNA and protein is normally silenced in most adult organs and may reappear during malignant transformation. In the past few years, immunohistochemical and molecular characteristics of glypican 3 in hepatocellular carcinoma have been elucidated. More recently, glypican 3 has been emerging as a new diagnostic marker for germ cell tumors and especially testicular and ovarian yolk sac tumors. However, in other tumors such as renal cell carcinomas, squamous cell carcinomas, and melanomas, studies disagree on the level of glypican 3 expression. Finally, there is the controversial notion of glypican 3 as a tumor suppressor gene. In this review article, we update current knowledge on glypican 3 expression in normal and neoplastic tissues, evaluate its utility as a tumor marker in clinical practice, and explore its role as a novel oncofetal protein with clinical implications. Our focus is on the diagnostic value of glypican 3 in germ cell tumors and other neoplasms in addition to hepatocellular carcinoma. In conclusion, glypican 3 has been proven to be a useful immunohistochemical marker in distinguishing yolk sac tumors, choriocarcinomas, and Wilms tumors from other malignancies histologically mimicking these primitive tumors. Clinically, we recommend that glypican 3 be used as part of a panel of markers in subtyping testicular germ cell tumors.

Immunohistochemical Study of Glypican-3 and HepPar-1 in Differentiating Hepatocellular Carcinoma from Metastatic Carcinomas in FNA of the Liver

Hepatocellular carcinoma (HCC) remains a common malignant cancer worldwide, it is considered the fifth most common malignant cancer. On the other hand, metastatic tumors are widespread in the liver , with metastatic adenocarcinoma (MA) constituting the greatest part, therefore differentiation of HCC from MA is a frequent problem facing the pathologist especially in liver fine-needle aspiration biopsies. Evaluating the diagnostic value of glypican-3 (GPC-3) and HepPar-1 immunostaining in differentiating hepatocellular carcinoma from metastatic tumors in liver cell block material. Fourty eight cell blocks prepared from FNA from the liver ( 30 cases HCC, 18 cases metastatic carcinoma in liver) stained by Glypican -3 and HepPar-1 immunohistochemical markers. Glypican-3 was immunoexpressed in 97% of cases of HCC while all cases of metastatic carcinoma were negative. HepPar-1 was expressed in 93% of cases of HCC and 11% of metastatic carcinoma of the liver. In this study the sensitivity of GPC3 in the diagnosis of HCC in cytological material was 96.7% and the specificity was 100% while the sensitivity and specificity of HepPar-1 was 93.3% and 88.9% respectively. Immunohistochemical staining for GPC-3 in cell block material of the liver is highly sensitive and specific and it is a valuable tool capable of differentiating HCC from most of metastatic tumors of the liver.

Arginase-1: a highly specific marker separating pancreatic adenocarcinoma from hepatocellular carcinoma

BACKGROUND

Arginase-1 and HepPar-1 are effective immunohistochemical (IHC) markers for hepatocellular carcinoma (HCC). In this study, we explored the possible efficacy of these stains in diagnosing pancreatic adenocarcinoma (PAD).

STUDY DESIGN

Arginase-1 and HepPar-1 IHC was performed on formalin-fixed, paraffin-embedded fine needle aspiration (FNA) cell blocks (CB) of PAD (n = 46), tissue microarray (TMA) of PAD (n = 33), FNA CB of HCC (n = 44) and TMA of HCC (n = 85). Negative controls without carcinoma were also applied (pancreas CB, n = 7; pancreas TMA, n = 3).

RESULTS

PAD CB demonstrated arginase-1 positivity in 0 of 46 cases and HepPar-1 positivity in 7 of 46 cases (15%). PAD TMA demonstrated arginase-1 positivity in 0 of 33 cases and HepPar-1 positivity in 4 of 33 cases (12%). HCC CB demonstrated arginase-1 positivity in 37 of 44 cases (84%) and HepPar-1 positivity in 32 of 44 cases (72%). HCC TMA demonstrated arginase-1 positivity in 75 of 85 cases (88%) and HepPar-1 positivity in 80 of 85 cases (94%).

CONCLUSION

Both arginase-1 and HepPar-1 are effective IHC markers of hepatocellular differentiation. Arginase-1 demonstrates superior sensitivity and specificity compared with HepPar-1 in the diagnosis of HCC. However, both arginase-1 and HepPar-1 have a low sensitivity and a very high specificity for PAD.

Clinical significance of the expression of long non-coding RNA HOTAIR in primary hepatocellular carcinoma

The functions of many long non-coding RNAs (ncRNAs) in human cancers have not yet been elucidated. The long ncRNA HOTAIR is expressed from the developmental HOXC locus located on chromosome 12q13.13. Previous reports have demonstrated that HOTAIR associates with chromatin modifications in cooperation with the Polycomb complex PRC2, and promotes breast and colorectal cancer metastasis. In this study, we examined the clinical significance of HOTAIR expression in patients with hepatocellular carcinoma (HCC). HOTAIR expression was detected in primary HCCs in 13 out of 64 patients. Patients with HOTAIR expression had significantly poorer prognoses and a larger primary tumor size than those without HOTAIR expression, similar to studies in breast and colorectal cancers. Moreover, introduction of human HOTAIR into liver cancer cells revealed that HOTAIR promoted more rapid proliferation compared to control cells. Thus, although the clinical significance of HOTAIR expression in HCC may not be as pronounced as that in breast and colorectal cancers, the current study demonstrates that HOTAIR expression is associated with HCC progression, warranting further studies.

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

Background

The ability to distinguish hepatocellular carcinoma (HCC) from metastatic carcinoma (MC) involving the liver and cholangiocarcinoma (CC) by immunohistochemistry has been limited by the lack of a reliable positive marker for hepatocellular differentiation. Arginase-1 is a marker for HCC recently described in some literature.

Aim

To examine the immunohistochemical staining of arginase-1 in cases of HCC, MC involving the liver and CC as compared to hepatocyte paraffin antigen -1 (HepPar-1) in an attempt to further define the diagnostic utility of arginase-1 in differentiating these tumors.

Materials and methods

A comparative immunohistochemical study of arginase-1 and HepPar-1expression was performed in 50 HCC cases, 38 cases of MC to the liver from varying sites, 12 cases of CC and 10 specimens of normal liver tissues. The predictive capacity of arginase-1 and HepPar-1 staining was determined using sensitivity, specificity, positive predictive value, and negative predictive value calculations.

Results

All normal liver tissues (no=10), non- neoplastic cirrhotic liver tissues adjacent to HCC (no=42) as well as those adjacent to MC (no= 9) showed diffuse and strong immunostaining for both arginase-1 and HepPar-1. Arginase-1 demonstrated positive immunoreactivity in 42 of 50 (84%) cases of HCC compared with 35 of 50 (70%) for HepPar-1. Only one of 38 (2.6%) cases of MC and one of 12 (8.3%) cases of CC showed positive immunoreactivity for arginase-1. In contrast, HepPar-1 immunoreactivity was detected in 6 of 38 (15.8%) cases of MC and in 2 of 12 (16.7%) cases of CC. Arginase -1 showed a significantly higher sensitivity for HCC diagnosis (84%) compared to HepPar -1(70%) (p=0.016). The specificity of arginase-1 for HCC diagnosis was higher (96%) than that of HepPar -1 (84%); nevertheless, this was not statistically significant (p=0.109). Howerver, the combination of both immunomarkers for the diagnosis of HCC, raised the specificity to 100%.

Conclusion

Arginase-1 immunostaining has a higher sensitivity and specificity than HepPar-1 for HCC diagnosis. Furthermore, the combined use of arginase-1 and HepPar-1 can provide a potentially promising tool to improve the accuracy in distinguishing HCC from metastatic carcinoma and cholangiocarcinoma.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9991436558072434.