Renal Cell Carcinoma in End-Stage Renal Disease: A Retrospective Study in Patients from Hungary.

INTRODUCTION: End-stage renal disease (ESRD) and acquired cystic kidney disease (ACKD) are known risk factors for renal cell carcinoma (RCC). Hereby, the clinicopathological features of RCCs developed in ESRD were investigated. METHODS: A database consisting of 34 tumors from 31 patients with ESRD among 2,566 nephrectomy samples of RCC was built. The demographic, clinical, and follow-up data along with pathological parameters were analyzed. The RCCs were diagnosed according to the current WHO Classification of Urinary and Male Genital Tumors. RESULTS: Twenty-two tumors developed in men and 12 in women, with a median age of 56 years (range: 27-75 years). The causes of ESRD were glomerulonephritis (n = 7), hypertensive kidney disease (n = 6), autosomal dominant polycystic kidney disease (n = 6), chronic pyelonephritis (n = 4), diabetic nephropathy (n = 3), chemotherapy-induced nephropathy (n = 1), and undetermined (n = 4). ACKD complicated ESRD in 12 patients. The following histological subtypes were identified: clear cell RCC (n = 19), papillary RCC (n = 5), clear cell papillary tumor (n = 5), ACKD RCC (n = 3), and eosinophilic solid and cystic RCC (n = 2). The median tumor size was 31 mm (range: 10-80 mm), and 32 tumors were confined to the kidney (pT1-pT2). There was no tumor-specific death during the period of this study. Progression was registered in 1 patient. CONCLUSION: In our cohort, the most common RCC subtype was clear cell RCC (55%), with a frequency that exceeded international data appreciably (14-25%). The incidence of clear cell papillary tumor and ACKD RCC (14.7% and 8.5%) was lower than data reported in the literature (30% and 40%). Our results indicate a favorable prognosis of RCC in ESRD.

Emerging human alveolar echinococcosis in Hungary (2003-2018): a retrospective case series analysis from a multi-centre study.

BACKGROUND: Human alveolar echinococcosis (AE) caused by Echinococcus multilocularis is an underreported, often misdiagnosed and mistreated parasitic disease mainly due to its low incidence. The aim of this study was to describe the epidemiological and clinical characteristics of human AE patients in Hungary for the first time. METHOD: Between 2003 and 2018, epidemiological and clinical data of suspected AE patients were collected retrospectively from health database management systems. RESULTS: This case series included a total of 16 AE patients. The mean age of patients was 53 years (range: 24-78 years). The sex ratio was 1:1. Four patients (25%) revealed no recurrence after radical surgery and adjuvant albendazole (ABZ) therapy. For five patients (31.3%) with unresectable lesions, a stabilization of lesions with ABZ treatment was achieved. In seven patients (43.8%), progression of AE was documented. The mean diagnostic delay was 33 months (range: 1-122 months). Three AE related deaths (fatality rate 18.8%) were recorded. CONCLUSIONS: AE is an emerging infectious disease in Hungary with a high fatality rate since based on our results, almost every fifth AE patient died in the study period. Differential diagnosis and appropriate surgical and medical therapy for AE is an urging challenge for clinicians in Hungary, as well as in some other European countries where E. multilocularis is prevalent.

Human cystic echinococcosis in Hungary (2000-2014): a retrospective case series analysis from a single-center study.

PURPOSE: Cystic echinococcosis (CE) is a parasitic disease caused by the tapeworm Echinococcus granulosus sensu lato. Although in Hungary the disease is listed among reportable infections, inadequacies in the reporting practice of CE by clinicians and pathologists have resulted in underscoring of this disease. The aim of this study was to describe the epidemiological and clinical characteristics of CE in Hungary using a datasource other than the official records that are based mainly on serological data. METHODS AND RESULTS: This retrospective case series study included a total of 45 CE patients confirmed by histopathology in a single Hungarian center between 2000 and 2014. CONCLUSION:  Although CE is the most prevalent reportable endemic helminthosis in Hungary, to date this is the first study on the clinical epidemiology of the disease in this country.

Alcohol disrupts levels and function of the cystic fibrosis transmembrane conductance regulator to promote development of pancreatitis.

BACKGROUND & AIMS: Excessive consumption of ethanol is one of the most common causes of acute and chronic pancreatitis. Alterations to the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) also cause pancreatitis. However, little is known about the role of CFTR in the pathogenesis of alcohol-induced pancreatitis. METHODS: We measured CFTR activity based on chloride concentrations in sweat from patients with cystic fibrosis, patients admitted to the emergency department because of excessive alcohol consumption, and healthy volunteers. We measured CFTR levels and localization in pancreatic tissues and in patients with acute or chronic pancreatitis induced by alcohol. We studied the effects of ethanol, fatty acids, and fatty acid ethyl esters on secretion of pancreatic fluid and HCO3(-), levels and function of CFTR, and exchange of Cl(-) for HCO3(-) in pancreatic cell lines as well as in tissues from guinea pigs and CFTR knockout mice after administration of alcohol. RESULTS: Chloride concentrations increased in sweat samples from patients who acutely abused alcohol but not in samples from healthy volunteers, indicating that alcohol affects CFTR function. Pancreatic tissues from patients with acute or chronic pancreatitis had lower levels of CFTR than tissues from healthy volunteers. Alcohol and fatty acids inhibited secretion of fluid and HCO3(-), as well as CFTR activity, in pancreatic ductal epithelial cells. These effects were mediated by sustained increases in concentrations of intracellular calcium and adenosine 3',5'-cyclic monophosphate, depletion of adenosine triphosphate, and depolarization of mitochondrial membranes. In pancreatic cell lines and pancreatic tissues of mice and guinea pigs, administration of ethanol reduced expression of CFTR messenger RNA, reduced the stability of CFTR at the cell surface, and disrupted folding of CFTR at the endoplasmic reticulum. CFTR knockout mice given ethanol or fatty acids developed more severe pancreatitis than mice not given ethanol or fatty acids. CONCLUSIONS: Based on studies of human, mouse, and guinea pig pancreata, alcohol disrupts expression and localization of the CFTR. This appears to contribute to development of pancreatitis. Strategies to increase CFTR levels or function might be used to treat alcohol-associated pancreatitis.

[Vitamin D metabolism and signaling in human hepatocellular carcinoma and surrounding non-tumorous liver]. / A D-vitamin metabolizmusa humán hepatocellularis carcinomában és az azt körülvevo tumormentes májszövetben.

INTRODUCTION: 1,25-Dihydroxy vitamin D3 mediates antitumor effects in hepatocellular carcinoma. AIM: We examined mRNA and protein expression differences in 1,25-Dihydroxy vitamin D3-inactivating CYP24A1, mRNA of activating CYP27B1 enzymes, and that of VDR between human hepatocellular carcinoma and surrounding non-tumorous liver. METHODS: Snap-frozen tissues from 13 patients were studied for mRNA and protein expression of CYP24A1. Paraffin-embedded tissues from 36 patients were used to study mRNA of VDR and CYP27B1. mRNA expression was measured by RT-PCR, CYP24A1 protein was detected by immunohistochemistry. RESULTS: Expression of VDR and CYP27B1 was significantly lower in hepatocellular carcinoma compared with non-tumorous liver (p<0.05). The majority of the HCC samples expressed CYP24A1 mRNA, but neither of the non-tumorous liver. The gene activation was followed by CYP24A1 protein synthesis. CONCLUSIONS: The presence of CYP24A1 mRNA and the reduced expression of VDR and CYP27B1 mRNA in human hepatocellular carcinoma samples indicate decreased bioavailability of 1,25-Dihydroxy vitamin D3, providing an escape mechanism from the anti-tumor effect. Orv. Hetil., 2016, 157(48), 1910-1918.

[The role of aspiration cytology in tumor diagnostics]. / Az aspirációs citológia szerepe a daganatdiagnosztikában.

Fine needle aspiration biopsy (FNAB) of focal lesions is a quick, relatively simple and cost-effective diagnostic method. However, performing aspirations and interpreting smears require skill and experience. Before initiating an aspiration the doctor needs to be aware of the limits of cytology as it is vital to know what kind of diagnostic issues can be answered upon a smear and what kind of questions cannot. Traditionally FNAB was performed without radiologic guidance, and therefore almost only palpable lesions were aspirated. Since ultrasound (US) has become widely used in medicine, it is axiomatical that FNAB is ideally performed with US guidance not only for the protection of the patients but also for targeting the lesion more safely. Several cytologists find US guidance unnecessary as a routinely used examination, which may lead to unsatisfactory smears and false negative results. This means not only a loss for the patient, but leads to a negative judgement of this diagnostic method. Our interventional cytology diagnostic team developed a working method resulting in excellent statistical results. In the followings we would like to share our experience refined the past two decades to restore the reputation of this diagnostic method.

[Significance of positive surgical margin in radical prostatectomy]. / A pozitív sebészi szél jelentõsége radikális prosztatektómia esetén.

The optimal oncological result of radical prostatectomy (RP) is complete removal of the prostate gland and seminal vesicles with negative surgical margins. Preoperative diagnostic biopsies are examined and reported by the pathologist according to standardized rules. Staging of the disease is based on modern preoperative image analysis, most commonly multiparametric MRI. Pathological assessment and reporting of RP specimens is based on the International Society of Uropathology guidelines issued by the 2009 Consensus Conference. Positive surgical margin (PSM) is reported by the pathologist in approximately 1/3rd of RP cases. PSM increases the risk of biochemical, local and systemic progression. Pseudo-whole mount assessment of these specimens is the basis for radio-pathological correlation, thus providing quality control for preoperative MRI as well as assisting preoperative image analysis, sampling and diagnostic workup.

Primary follicular dendritic cell sarcoma of the kidney - a case report of a rare tumor with emphasis on diagnostic pitfalls.

BACKGROUND: Follicular dendritic cell sarcoma (FDCS) is a rare low-grade tumor of the lymph nodes, but roughly one-third of the cases emerge from extranodal sites, posing diagnostic challenges. CASE PRESENTATION: In this report, we present the case of a 59-year-old lady who complained of renal colic. During investigation, a kidney tumor was discovered. A radical nephrectomy was performed, and histological examination identified the tumor as a sarcomatoid renal cell carcinoma. The case was then referred to a genitourinary pathologist for further evaluation. The tumor cells exhibited positive staining for CD21, CD23, somatostatin receptor 2 A, and MDM2 expression. Additionally, MDM2 gene amplification was confirmed by the FISH study. Ultimately, the tumor was diagnosed as a primary renal FDCS. The patient was placed under active oncological surveillance and did not receive any further therapy. Remarkably, after 91 months of follow-up, she remains tumor-free. CONCLUSION: This case represents a well-documented primary renal FDCS. Our aim in presenting this extremely rare tumor is to enhance awareness and highlight the importance of considering FDCS in the differential diagnosis.

Tricellulin expression in normal and neoplastic human pancreas.

AIMS: Tricellulin is a member of the family of tight junction proteins, which are found concentrated mainly at tricellular contacts. Altered expression of several tight junction components has been observed during carcinogenesis. In the present study, we have analysed the expression of tricellulin in normal human pancreas, and in primary exocrine and endocrine pancreatic tumours. METHODS AND RESULTS: A total of 96 cases were studied: 20 normal pancreas, 58 pancreatic ductal adenocarcinomas, 15 pancreatic endocrine neoplasms, and three acinar cell carcinomas. Immunohistochemistry (analysed by digital morphometry), immunofluorescence, western blot analysis and reverse transcription polymerase chain reaction were performed. Tricellulin was localized apically in normal ducts and acini as intensive, spotty immunopositivity at tricellular contacts, whereas weaker signals were observed at the junction between two cells. Islets of Langerhans were negative. Well-differentiated ductal adenocarcinomas significantly overexpressed tricellulin as compared with poorly differentiated adenocarcinomas. Acinar cell carcinomas expressed tricellulin in tumour cells. All endocrine tumours were tricellulin-negative. CONCLUSIONS: This is the first report to describe the tricellulin expression profile in normal and neoplastic human pancreas. Both normal and neoplastic pancreatic exocrine tissues expressed tricellulin, whereas no expression was seen in normal or neoplastic endocrine cells. Tricellulin expression in pancreatic ductal adenocarcinomas showed a significant negative correlation with the degree of differentiation.

[The pathogenic role of uterine erythropoietin in a case of myomatous erythrocytosis syndrome]. / Egy myomás erythrocytosis esetrol és a méh eredetu erythropoetin fiziopatológiájáról.

We report the case of a 50-year-old woman with severe erythrocytosis and uterine leiomyoma. The suspicion of myomatous erythrocytosis syndrome was supported by erythropoietin level higher than expected. After the supravaginal hysterectomy, the patient's red cell parameters normalized and the erythropoietin level markedly decreased. The authors are discussing the physiology of uterine erythropoietin, the evaluation and differential diagnostic value of erythropoietin investigations. Orv Hetil. 2022; 163(52): 2088-2092.

Renal Cell Carcinoma with Clear Cell Papillary Features: Perspectives of a Differential Diagnosis.

Thirty-one cases of low-grade renal cell carcinoma (RCC) with clear cells and tubulopapillary/papillary architecture were analyzed retrospectively with immunohistochemical and genetic markers to gain more experience with the differential diagnosis of such cases. All samples coexpressed CK7 and CA9; the TFE3 or TFEB reactions were negative; the CD10 and the AMACR stainings were negative in 27 cases and 30 cases, respectively. The FISH assays for papillary RCC, available in 27 cases, and deletion of chromosome 3p, available in 29 cases, gave negative results. The results for 3p deletion, VHL gene mutation or VHL gene promoter region hypermethylation testing, along with the diffuse CD10-positivity in 2 cases confirmed 21 cases as clear cell papillary RCC (CCPRCC; CK7+, CA9+; no 3p loss, no VHL abnormality) and 10 cases as clear cell RCC (CCRCC; CK7+, CA9+; no 3p loss, VHL abnormality mutation/hypermethylation present). In CCPRCCs, the representative growth pattern was branching tubulo-acinar, commonly accompanied by cyst formation. The linear nuclear arrangement or cup-shaped staining of CA9 did not necessarily indicate CCPRCC, and the absence of these did not exclude the diagnosis of CCPPRC. One tumor infiltrated the renal sinus; the others exhibited pT1 stage; and metastatic outcome was not recorded. The CCRCC cases were in pT1 stage; 6 exhibited cup-shaped staining of CA9, and 1 displayed lymph node metastasis at the time of surgery. Distant metastatic disease was not observed. In summary, the VHL abnormalities distinguished the subset of CCRCC with diffuse CK7-positivity and no 3p loss from cases of CCPRCC.

Clinicopathological Findings on 28 Cases with XP11.2 Renal Cell Carcinoma.

Xp11.2 translocation carcinoma is a distinct subtype of renal cell carcinoma characterized by translocations involving the TFE3 gene. Our study included the morphological, immunohistochemical and clinicopathological examination of 28 Xp11.2 RCCs. The immunophenotype has been assessed by using CA9, CK7, CD10, AMACR, MelanA, HMB45, Cathepsin K and TFE3 immunostainings. The diagnosis was confirmed by TFE3 break-apart FISH in 25 cases. The ages of 13 male and 15 female patients, without underlying renal disease or having undergone chemotherapy ranged from 8 to 72. The mean size of the tumors was 78.5 mm. Forty-three percent of patients were diagnosed in the pT3/pT4 stage with distant metastasis in 6 cases. Histological appearance was branching-papillary composed of clear cells with voluminous cytoplasm in 13 and variable in 15 cases, including one tumor with anaplastic carcinoma and another with rhabdoid morphology. Three tumors were labeled with CA9, while CK7 was negative in all cases. Diffuse CD10 reaction was observed in 17 tumors and diffuse AMACR positivity was described in 14 tumors. The expression of melanocytic markers and Cathepsin K were seen only in 7 and 6 cases, respectively. TFE3 immunohistochemistry displayed a positive reaction in 26/28 samples. TFE3 rearrangement was detected in all the analyzed cases (25/25), including one with the loss of the entire labeled break-point region. The follow-up time ranged from 2 to 300 months, with 7 cancer-related deaths. In summary, Xp11.2 carcinoma is an uncommon form of renal cell carcinoma with a variable histomorphology and rather aggressive clinical course.

Claudin-1, -2, -3, -4, -7, -8, and -10 protein expression in biliary tract cancers.

Biliary tract cancers are relatively common malignant gastrointestinal tumors in the elderly. Claudins are integral components of tight junctions that play important roles in maintaining epithelial cell polarity, controlling paracellular diffusion, and regulating cell growth and differentiation. The expression profile of claudins has been extensively characterized, but few reports exist on their expression in the normal and neoplastic biliary tract. Our aim was therefore to study claudins by IHC reactions in normal and neoplastic biliary tract samples. We detected that claudin expressions differ in the normal sample groups: the normal gallbladder strongly expressed claudin-2, -3, -4, and -10, but only weak reactions were seen in normal intrahepatic bile ducts. Although each cancer type expressed several claudins with various intensities, only claudin-4 presented especially strong immunoreactions in extrahepatic bile duct cancers and gallbladder carcinomas, whereas claudin-1 and -10 presented in intrahepatic bile duct cancers. Comparing the normal and carcinoma groups, the most significant decrease was detected in the expression of claudin-10. In conclusion, the expression pattern of claudins is different in the various parts of the normal and neoplastic biliary tract; moreover, an unequivocal decrease was detected in the carcinomas compared with their corresponding normal samples. This manuscript contains online supplemental material at http://www.jhc.org. Please visit this article online to view these materials.

[Functional mRNA expression analysis and classification of colonic biopsy samples using overall cDNA microarray technique]. / Vastagbél-biopszia funkcionális mRNS-expressziós vizsgálata és osztályozása általános cDNS microarray technikával.

BACKGROUND: Overall mRNA expression analysis of colon biopsies can contribute to the understanding of molecular background of the local alterations and gene ontology-based functional classification of colonic biopsies into inflammatory and neoplastic diseases. METHODS: Total RNA was extracted from frozen biopsies and amplified by T7-method. Expression profile was evaluated by Atlas Glass 1K microarrays. After microarray quality control, applicable data were available from 10 adenomas, 6 colorectal adenocarcinoma (CRC), and inflammatory bowel diseases (IBDs: 3-3 CD and UC). Multivariate statistical and cell functional analyses were performed. Real-time RT-PCR and immunohistochemistry were used for validation. RESULTS: Discriminant analysis of selected genes could correctly reclassify all 22 samples using 4 parameters (heat shock transcription factor-1, bystin-like, calgranulin-A, TRAIL receptor 3). IBD samples were characterized by overregulated chemokine (C-X-C motif) ligand 13, replication protein A1, E74-like factor 2 and downregulated TNF receptor-associated factor 6, BCL2-interacting killer genes. In adenomas upregulation of TNF receptor-associated factor 6, replication protein A1, E74-like factor 2 and underexpression of BCL2-associated X protein, calgranulin-A genes were found. CRC cases had significantly increased epidermal growth factor receptor, topoisomerase-1, v-jun, TNF receptor-associated factor 6 and TRAIL receptor 3, and decreased RAD51 and RAD52 DNA repair gene, protein phosphatase-2A and BCL2-interacting killer mRNA levels. Epidermal growth factor receptor RT-PCR and immunohistochemistry, topoisomerase-1 RT-PCR confirmed the chip results. CONCLUSIONS: Different histological alterations can be objectively classified by functional, multivariate analysis using cDNA microarrays. Disease-specific gene expression patterns can assist to avoid the intermediate and nondescript cases in diagnostics, which do not belong to any of the conventional diagnostic groups.

Successful treatment of three synchronous primary malignant tumours-reflection on surgical, pathological and oncological aspects and decision making.

We report a case of a patient with triple synchronous primary malignancies (breast, colon, kidney) which has not been previously reported in the literature. A 70-year-old woman was diagnosed with invasive ductal carcinoma of the left breast with axillary lymph node metastasis. During the staging period, renal cell carcinoma on the left kidney and mucinous adenocarcinoma in the proximal colon were found. Since the breast tumour demonstrated favourable biology, aromatase inhibitor therapy had been started and simultaneous right colectomy and left nephrectomy was performed. Six months after the first diagnosis, left sector excision and axillary block dissection were performed. Adjuvant FEC chemotherapy was administered, followed by radiotherapy. During the 16-month follow-up period disease recurrence was not detected.

Tricellulin expression and its prognostic significance in primary liver carcinomas.

Numerous data suggest that altered expression of tight junction proteins such as occludin and claudins plays important role in carcinogenesis. However, little is known about tricellulin, a transmembrane tight junction protein concentrated where three epithelial cells meet. We aimed to characterize tricellulin expression in normal and cirrhotic liver in comparison to primary hepatic neoplasms. Tricellulin expression of 20 control livers, 12 cirrhotic livers, 32 hepatocellular carcinomas (HCC), and 20 intrahepatic cholangiocarcinomas (iCCC) was investigated by immunohistochemistry and Western blotting. Co-localization of tricellulin with claudin-1, -4, and MRP2 was studied using double immunofluorescence. Scattered tricellulin immunopositivity was restricted to biliary pole of hepatocytes confirmed by co-localization with MRP2. Moreover, spotted-like reaction was observed between bile duct epithelial cells. In 40 % of HCCs marked tricellulin overexpression was measured regardless of tumor grades. In iCCCs, however, tricellulin expression decreased parallel with dedifferentiation. In HCCs high tricellulin expression, in iCCCs low tricellulin expression correlated with poor prognosis. Co-localization with MRP2 might substantiate that tricellulin plays role in blood-biliary barrier. Overexpressed tricellulin in a subset of HCCs correlated with unfavorable prognosis. Similar to ductal pancreatic adenocarcinoma, higher grades of iCCCs were associated with decreased tricellulin expression correlating with poor prognosis.

Molecular characteristics of fibrolamellar hepatocellular carcinoma.

Fibrolamellar hepatocellular carcinoma (FLC) occurs in non-cirrhotic liver and the etiopathogenesis is still obscure. Both hepatocellular and cholangiocellular markers are expressed in the tumor, however, molecular alterations and altered pathways playing role in the tumor pathogenesis are not clearly identified. The purpose of the present study was to compare the expression level of EGFR, syndecan-1 and ß-catenin in FLC, conventional hepatocellular carcinoma (cHCC) and cholangiocellular carcinoma (CCC) and to investigate the possibility of mutation both in EGFR and K-RAS. Eight FLCs were compared with 7 cHCCs, 7 CCCs and 5 normal liver samples. Cytokeratins 7, 8, 18, 19, HepPar1 (HSA), EGFR, syndecan-1 (CD138) and ß-catenin were detected by immunohistochemistry. In addition EGFR, ß-catenin and syndecan-1 were evaluated by digital morphometry and K-RAS, EGFR mutations in FLC cases using paraffin-embedded samples. All FLCs were positive for HepPar1 (HSA) and cytokeratins 7, 8, 18, but negative for cytokeratin 19 by immunohistochemistry. EGFR was significantly overexpressed in all three tumor types, being highest in FLCs (p = 0,0001). EGFR, K-RAS mutation analyses revealed no mutations in exons studied in FLCs. Our findings proved that expression of EGFR is higher in FLC than in other types of primary malignant hepatic tumors and no K-RAS mutation can be detected, so FLC is a good candidate for anti-EGFR treatment.

Claudins and ki-67: potential markers to differentiate low- and high-grade transitional cell carcinomas of the urinary bladder.

Updated classification of urothelial cell cancer differentiates low-grade and high-grade cancers, which determines potential clinical outcome. Substantial interobserver variability necessitates new biomarkers to ensure classification. Claudins' specific expression pattern characterizes normal tissues, different tumor types, and defined grades of tumor differentiation. The aim of this study was to examine the expression pattern of claudins and proliferation marker Ki-67 in low-grade and high-grade urothelial cell cancers compared with independent control samples of non-tumorous urothelium, as well as to reveal the predictive usefulness of claudins. The expression of claudins-1, -2, -3, -4, -5, -7, and -10 and Ki-67 was studied with quantitative immunohistochemistry and real-time RT-PCR with relative quantification in 103 samples: 86 urothelial cell cancers (27 low grade, 59 high grade) and 17 non-tumorous urothelia. Results were analyzed regarding overall survival and recurrence-free period as well. High-grade tumors overall showed significantly higher claudin-4 and Ki-67 and significantly lower claudin-7 expression when compared with low-grade ones. High-grade tumors revealed significantly shorter overall survival in Kaplan-Meier analysis. Claudin-4, claudin-7, and Ki-67 might be used as potential markers to differentiate low-grade and high-grade urothelial cell cancers, thereby possibly enhancing accuracy of pathological diagnosis and adding further information to clinical outcome.

Claudins and tricellulin in fibrolamellar hepatocellular carcinoma.

Fibrolamellar hepatocellular carcinoma is a subtype of hepatocellular carcinoma occurring in non-cirrhotic liver at a younger age. The tumor expresses both hepatocellular and cholangiocellular markers. Previously, our group described overexpression of tight junction protein claudin 4 in cholangiocellular carcinoma in contrast to hepatocellular carcinoma. In the present study, tight junction protein expressions were studied to possibly clarify bipotential lineage of fibrolamellar hepatocellular carcinoma. Eleven fibrolamellar hepatocellular carcinomas were compared with seven "conventional" hepatocellular carcinomas, seven cholangiocellular carcinomas, and five normal liver samples. By immunohistochemistry, all fibrolamellar hepatocellular carcinomas were positive for HepPar1 and cytokeratins 7, 8, and 18, but negative for cytokeratin 19. Glypican-3 gave weak staining in two cases. Expression of claudin 1 was lower, while that of claudin 2 was higher in fibrolamellar hepatocellular carcinomas than in other tumors. Claudins 3, 4, and 7 were not detectable in fibrolamellar hepatocellular carcinomas as in the majority of "conventional" hepatocellular carcinomas, contrary to high expression observed in cholangiocellular carcinomas. Focal or diffuse claudin 5 expression was detected in nine of 11 fibrolamellar hepatocellular carcinomas contrary to other tumors. Tricellulin was significantly downregulated in all tumors compared with normal liver. Our findings showed claudins to exhibit specific expression patterns in fibrolamellar hepatocellular carcinomas not observed in other primary liver tumors, with unique claudin 5 expression and pattern features similar to common hepatocellular carcinoma, but different from cholangiocellular carcinoma. This is the first report describing the loss of tricellulin expression in human hepatic tumors.

Agrin immunohistochemistry facilitates the determination of primary versus metastatic origin of liver carcinomas.

In our earlier work, we demonstrated that agrin, a multifunctional heparan sulfate proteoglycan, accumulates in hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC). In addition, we proved the utility of agrin immumohistochemistry in discriminating between HCCs and benign parenchymal lesions. Here, we have examined the expression of agrin in metastatic liver carcinomas in comparison with primary liver tumors. Immunohistochemistry for agrin was performed on 25 HCC, 16 intrahepatic CCC, 20 colorectal cancer metastasis (CRCm), and 18 pancreatic ductal carcinoma metastasis (PDCm) samples and evaluated with both quantitative and qualitative methods. Agrin/CD34 double immunofluorescent staining was carried out on snap-frozen sections. Agrin mRNA expression was measured in 11 HCC, 7 CCC, 11 CRCm, and 12 normal liver tissues. Regardless of tumor grade, agrin immunostaining was strong in the microvessels of HCCs. As opposed to HCC, agrin immunostaining was faint or nearly absent from the CD34-positive microvessels of CCC, CRCm, and PDCm; rather, it was detected in the basement membranes surrounding tumor cell pseudoglandules. While agrin was preserved in the basement membranes of Grade III CCCs, it was nearly absent from poorly differentiated metastatic adenocarcinomas. Agrin mRNA levels were the highest in CCC and lower, but still elevated in HCC and CRCm. By qualitative evaluation of agrin immunoreactions, CCC was differentiated from CRCm and PDCm with a sensitivity of 0.81 and a specificity of 0.82. HCCs were unequivocally identified on the basis of microvascular agrin labeling. Thus, agrin immunohistochemistry may facilitate determination of primary versus metastatic origin in problematic liver cancer cases.