PAX-5 positive anaplastic large cell lymphoma presenting by dysphagia; a case report.

Anaplastic large cell lymphoma (ALCL) is a distinct pathologic entity with characteristic morphologic, im¬munophenotypic and cytogenetic features. Obstructive symptoms are rare presentation of ALCL. We report a 16-year-old boy who initially presented with dysphagia. Upper gastrointestinal endoscopy revealed severe stenosis with an infiltrative process starting from 24 cm of incisors in lower esophagus Esophageal mucosal biopsy demonstrated lymphomatous involvement that ancillary tests confirmed the diagnosis of ALCL, ALK (kinase-positive), and PAX5 positive. The patient responded to CHOP-based chemotherapy. This case illustrated an unusual presentation of primary Non Hodgkin lymphoma of esophagus.

Gelatin for purification and proliferation of primary keratinocyte culture for use in chronic wounds and burns.

OBJECTIVES: Human epidermal keratinocytes are currently established as a treatment for burns and wounds and have laboratory applications. Keratinocyte culture contamination by unwanted cells and inhibition of cell proliferation are barriers in primary keratinocyte culture. According to the recent literature, these cells are hard to culture. The present study was conducted to evaluate the efficacy of gelatin-coated surfaces in keratinocyte cultures. MATERIALS AND METHODS: After enzymatic isolation of keratinocytes from normal epidermis by trypsin, the cells were cultured on gelatin-coated flasks in serum-free medium. Another group of cells were cultured as a control group without gelatin coating. RESULTS: We showed positive effects of surface coating with gelatin on the primary culture of keratinocytes. Culture of these cells on a gelatincoated surface showed better proliferation with suitable morphology. By using gelatin, adhesion of these cells to the surface was more efficient and without contamination by small round cells. CONCLUSIONS: Successful primary culture of keratinocytes on a gelatin-coated surface may provide better yield and optimal number of cells for research and clinical applications.

Considerations in the improvement of human epidermal keratinocyte culture in vitro.

OBJECTIVES: Large-scale expansion of epidermal keratinocytes is essential in the application of these cells for severe burn treatment in patients. Therefore, this study was designed to evaluate various conditions in the expansion of human epidermal keratinocytes. MATERIALS AND METHODS: The epidermis was separated from the dermis of skin samples using dispase. The epidermis was trypsinized for keratinocyte isolation. Keratinocytes were cultured in various conditions, with or without a human dermal fibroblast feeder layer, mitomycin C treatment, and different culture media. RESULTS: Our results suggest that keratinocytes cultured on a human dermal fibroblast feeder layer were grown for several passages. Extensive deformation and rapid deterioration were observed in the cultured cells without a feeder layer and in serum-free medium. CONCLUSIONS: Human dermal fibroblasts treated with mitomycin C can provide optimal conditions for proliferation of keratinocytes.

Cytotoxicity of chlorhexidine-hydrogen peroxide combination in different concentrations on cultured human periodontal ligament fibroblasts.

BACKGROUND: A strong antimicrobial synergism between chlorhexidine (CHX) and hydrogen peroxide (H2O2) has been reported, but there is not enough data on the cytotoxicity of this combination. The primary aim of this study was to evaluate the cytotoxicity of CHX-H2O2 combination in different concentrations and secondary aim is to assess the influence of H2O2 on cytotoxicity of CHX on cultured human periodontal ligament (PDL) fibroblasts. MATERIALS AND METHODS: The PDL cells were cultured from healthy human third molar teeth and were exposed to six prepared solutions (0.2% and 2% CHX separately and in combination with 1% and 3% H2O2). The MTT assay was applied to assess their effects on the viability of the PDL cells. Two-way analysis of variance approach and subgroup analysis was performed to evaluate the differences in mean cell viability values. A level of P < 0.05 was considered as statistically significant. RESULTS: All tested solutions were toxic to PDL cells. There was a significant interaction effect between CHX and H2O2. The 2% CHX combined with 3% H2O2 was the most and 0.2% CHX was the least cytotoxic solutions. The 2% CHX was significantly more toxic than 0.2% CHX and H2O2 combinations. The cytotoxicity of 0.2% CHX and H2O2 combinations did not significantly rise by increasing the concentration of H2O2 from 1% to 3%. CONCLUSION: H2O2 affected the cytotoxicity of CHX in a variable concentration-dependent manner. Based on the results of this study, it can be concluded that 2% CHX alone and in combination with either 1 or 3% H2O2 are significantly more toxic than 0.2% CHX alone and in combination with 1 and 3% H2O2. Therefore, to benefit from the synergistic antimicrobial effect between CHX and H2O2, with a minimal cytotoxicity, it is recommended to use 0.2% concentration of CHX combined with 3% H2O2.

High-risk human papillomavirus infection in different histological subtypes of renal cell carcinoma.

Limited data exist regarding whether a high-risk human papillomavirus (HR-HPV) infection increases the risk of developing renal cell carcinoma. The aim of this study was to investigate whether HPV infection has a role in the pathogenesis or development of a certain histological subtype of renal cell carcinoma. Formalin-fixed paraffin-embedded (FFPE) specimens of 122 patients with histopathologically proven renal cell carcinoma and their respective peritumoral tissues were examined. The presence of HPV-DNA was determined by a combination of MY/GP+ consensus primers and HPV-16/18 type specific nested PCRs followed by direct sequencing. Catalyzed signal-amplified colorimetric in situ hybridization (CSAC-ISH) technique was applied to determine the physical status of viral genome. The expression of p16INK4a and HPV L1 capsid proteins was evaluated using immunohistochemistry. HPV genome was detected in 37 (30.3%) tumor specimens and their four (4.1%) corresponding peritumoral tissues. HPV-18 was the most common viral type identified followed by HPV-16 and 58. Immunoexpression of p16INK4a was detected in 24 (20.3%) cases. Data analysis showed a significant correlation between p16INK4a expression and the presence of HR-HPV DNA (P < 0.001). CSAC-ISH analysis confirmed HR-HPV infection in 45% of tumors, which were previously tested positive for HPV-DNA. Diffuse signal pattern was identified in 15 (83.3%) samples whereas a mixed pattern of diffuse and punctate signals was only detectable in three cases. The results indicate an association of HR-HPV types with renal cell carcinoma. It is proposed that HPV infection in high-grade tumors might precede disease progression in a number of tumors, particularly of the papillary subtype.

Hepatocyte isolation from unused/rejected livers for transplantation: initial step toward hepatocyte transplantation, the first experience from iran.

BACKGROUND: Hepatocyte transplantation is being used in patients with liver-based metabolic disorders and acute liver failure. Hepatocytes can be isolated from unused/rejected livers under sterile conditions. OBJECTIVES: The quality of the hepatocytes is very important and the main and initial step in hepatocyte transplantation is hepatocyte isolation. In this study we tried to set up the methods of hepatocyte isolation in order to use the high quality cells in acute liver failure or congenital metabolic disorders. MATERIALS AND METHODS: In this study, during a year, hepatocytes were isolated from 7 unused/rejected livers among more than 300 harvested livers in Shiraz University of Medical Sciences. The two step collagenase perfusion method was used under GMP (Good manufacturing practice) for hepatocyte isolation. RESULTS: Highly quality hepatocytes with high viability and low contamination were isolated. The mean viability was 71.8% ± 21.7. In the first 4 cases microbial contamination by Staphylococci, Diphtheroid and Klebsiella was detected, however the last 3 cases were free of any micro organisms. After 5 weeks of cryopreservation in -140°C, the cell viability was still acceptable. CONCLUSIONS: Hepatocyte isolation can be performed as the main and initial step for cell transplantation from unused/rejected liver. It is the first experience in Iran.

Vitamin D receptor genotype in pancreas allograft: a pilot study.

OBJECTIVES: Transplanting of pancreatic grafts is an established treatment for diabetes mellitus. Polymorphisms in genes, coding for proteins involved in an immune response, may influence immunologic and nonimmunologic mechanisms that lead to allograft loss. Vitamin D receptor agonists have been shown to increase long-term allograft survival in humans. MATERIALS AND METHODS: Twenty-one pancreatic recipients transplanted in the Transplantation center of Shiraz University of Medical Sciences were selected and genotyped for the polymorphism of the vitamin D receptor genes (FokI), and the association of each genotype with acute rejection was evaluated. A control group of 100 unrelated otherwise healthy individuals, from the Iranian Blood Transfusion Organization were enrolled. The individuals were selected from Shiraz (a city located in Southern Iran), and the genotype frequency was compared with control group. RESULTS: The overall prevalence acute rejection was 28% (6/21). In the genotype study, homozygous FF presented in 15 patients (71%), heterozygous Ff presented in 6 patients (29%), and no homozygous ff was identified. In the control group, there were 50% with FF, 48% with Ff, and 2% with the ff genotype identified. The only genotype that was detected in rejection group was FF, while the frequency of FF in the nonrejection group was 60%. CONCLUSIONS: This study examined several patients to determine whether the vitamin D receptor (FokI) genotype is involved in acute allograft rejection and requires deeper investigation.

Association between tacrolimus concentration and genetic polymorphisms of CYP3A5 and ABCB1 during the early stage after liver transplant in an Iranian population.

OBJECTIVES: Tacrolimus is widely used as an immunosuppressive drug in liver transplant recipients with a narrow therapeutic range and variable individualized pharmacokinetics. Tacrolimus is a substrate of cytochrome P-450 3A enzyme and the drug transporter, P-glycoprotein. MATERIALS AND METHODS: We determined the genotypic frequencies of cytochrome P-4503A5 (rs776746), and ABCB1 (rs1045642), single nucleotide polymorphisms in a population of 100 Iranian liver transplant patients, and investigated the influence of the above-mentioned single nucleotide polymorphisms on tacrolimus concentrations. At 7 and 30 days after transplant, tacrolimus dosages (mg/kg/d), trough blood levels (T0), and dose-adjusted concentrations (concentration/dosage ratio) were determined. Polymerase chain reaction, followed by restriction fragment length polymorphism analysis, was used for genotyping cytochrome P-4503A5*3 [6986A>G] as well as ABCB1 [3435C>T]. RESULTS: Ninety-five percent of the population showed a cytochrome P-4503A5*3/*3 genotype. ABCB13435TT genotype was observed in 33 cases (33%); whereas 51 cases (51%) carried 3435CT, and 16 cases (16%) carried 3435CC. With regard to the ABCB1 and cytochrome P-4503A5, they showed no influence on tacrolimus dosing requirements at 1 week or 1 month after transplant. No association of any genetic variant with the acute rejection rate was found. CONCLUSIONS: Finally, as the liver donor genotype influences tacrolimus pharmacokinetics with regard to expression of cytochrome P-4503A5, far more than the genotype of the recipient; therefore, it should be considered before recommending any personal immunosuppressive treatment based on pharmacogenetics.

Role of viruses in renal cell carcinoma.

To determine whether viral infections are related to renal cell carcinoma (RCC), we studied 49 patients with RCC (29 patients were males with age ranging from 30 to 81 years and a mean of 57.5 years; 20 patients were females with age ranging from 36 to 70 years with a mean of 58.4 years) and 16 non-neoplastic kidney patients as controls. Tissues specimens from study patients and controls were examined by nested polymerase chain reaction (PCR) to determine the presence of DNA of several viruses including human papilloma virus (HPV), Epstein-Barr virus (EBV), and polyoma viruses (BKV and JCV). Our results revealed that 7 of 49 (14.29%) RCC tissue specimens had HPV DNA compared with none of 16 non-cancer control subjects. Regarding the HPV types, all the positive results were high-risk HPV types (type 16 in three and 18 in four patients). The present study suggests that HPV infection, especially high-risk types, is associated with RCC. However, more studies are necessary to demonstrate the molecular oncogenic processes involved in this association.

Mucin profile expression in gastric adenocarcinoma.

BACKGROUND: The process of neoplastic transformation in the stomach has been reported to be associated with decreased expression of normal mucins of the gastric mucosa and denovo expression of mucins that are normally expressed in other organs. This association may be used as a means to bring new insights into biologic behavior and genetic pathways in the development of gastric cancer. There are controversial reports about differences in the genetic pathway and behavior of gastric cancer in younger patients in comparison with older ones. This study aims to determine if there is any difference in mucin profiles between different age groups with gastric cancer. METHODS: Over a five-year (2003-2008) period, 43 cases of gastric cancer (≤50) years were referred to our center. Of these, 40 had adequate tissue for additional study, whereas three cases lacked a sufficient amount of tumor tissue for immunohistochemistry (IHC) analysis. A group of 40 gastric cancer patients above the age of 50 years were gender-matched with the first group. Expressions of MUC-1, MUC-2, MUC-5AC, and MUC-6 were evaluated by IHC for the total 80 gastric cancer cases. RESULTS: The expressions of the mucins did not show a significant difference between the two age groups. CONCLUSION: Gastric cancer in both young and old age adults was not significantly different in terms of mucin profiles. Our results have shown that younger age is not predictive of gastric cancer phenotype, which can be an indicator of the lack of difference in the genetic pathways and molecular alterations in these two age groups.

Thiopurine S-methyltransferase polymorphism in Iranian kidney transplant recipients.

OBJECTIVES: Thiopurine S-methyltransferase is an enzyme that catalyzes S-methylation of azathioprine as an immunosuppressive drug. Genetic polymorphisms influence thiopurine S-methyltransferase activity. There are 3 variant alleles: thiopurine S-methyltransferase*2, *3A, and *3C are responsible for more than 95% cases of low-enzyme activity. MATERIALS AND METHODS: We studied these polymorphisms and the occurrence of azathioprine adverse effects in 50 renal transplant recipients undergoing triple immunosuppressive therapy including azathioprine, cyclosporine, and prednisone. Thiopurine S-methyltransferase genetic polymorphism was determined by polymerase chain reaction restriction fragment length polymorphism assay and allele-specific polymerase chain reaction methods. Azathioprine dosage; leukocyte, erythrocyte, and platelet counts; and graft rejection episodes were analyzed during hospitalization. RESULTS: Two patients (2%) were heterozygous for thiopurine S-methyltransferase*3C, the remaining patients were thiopurine S-methyltransferase wild-type *1/*1 (98%). Thiopurine S-methyltransferase wild-type homozygous and heterozygous patients were administered similar azathioprine dosages at the beginning of treatment (2.42 ± 0.50 and 2.52 ± 0.40 mg/kg/24 h). During subsequent days, mean azathioprine dosage administered to thiopurine S-methyltransferase wild-type homozygous patients was similar to heterozygous patients, but with no statistical difference (P = .28). Three patients had an acute rejection episode during this time. Five patients (10%) had reduced azathioprine dosage owing to adverse effects. Adverse reactions consisted of hematotoxicity (n=2), hepatotoxicity (n=1), and gastrointestinal toxicity (n=2). All recipients were wild-type homozygotes. CONCLUSIONS: The frequency of thiopurine S-methyltransferase gene mutations is low among our patients. The incidence of adverse reactions to azathioprine was also low, even in patients carrying a variant of thiopurine S-methyltransferase. We conclude that determining thiopurine S-methyltransferase genotype is not useful in our population to predict adverse reactions to azathioprine.

Human herpesvirus-6 viral load and antibody titer in serum samples of patients with multiple sclerosis.

BACKGROUND: Despite the number of cases with definite diagnosis of multiple sclerosis (MS) being on increase, the role of human herpesvirus-6 (HHV-6) infection as a trigger for MS disease still is deliberated. Based on antibody detection and quantitative HHV-6 polymerase chain reaction assay, this study was achieved to find out the possible association between infection with HHV-6 and clinical progression of MS disease. METHODS: A total of 108 serum samples were obtained from 30 MS patients followed prospectively for a 6-month period. These samples were analyzed for the presence of HHV-6 DNA by nested polymerase chain reaction enzyme-linked immunosorbent assay and for anti-HHV-6 IgG titer. Activation of the disease was determined by either magnetic resonance imaging or by clinical status of the patients. Control groups were also included. RESULTS: The average antibody index for the MS patients in the first sample collection was higher than both control groups (p = 0.001). HHV-6 DNA was detected in the serum samples of 10 of 30 MS patients. The mean HHV-6 viral load in patients with relapsing-remitting multiple sclerosis (RRMS) with and without relapse was 973 and 714, respectively. Seven patients showed an exacerbation during the study period. Of those, four patients had HHV-6 DNA in their collected samples. The prevalence of HHV-6 DNA was significantly higher in patients with MS as compared with control groups (p = 0.001). CONCLUSIONS: The results indicate that HHV-6 is implicated somehow in MS disease. Over time, rising HHV-6 IgG antibody titers together with an exacerbation and detection of HHV-6 DNA in serum samples of some MS patients suggests possible association between the reactivation of the virus and disease progression.

Study of viral infections in infants with biliary atresia.

Viral infections may have an important role in the pathogenesis of biliary atresia, and related clinical outcomes. In this research for determination of the possible role of HBV, HCV, HCMV, adenovirus, and BK virus infections in biliary atresia related clinical complications, the molecular and antigenic prevalence of these viral agents were studied. In this retrospective study, 34 formalin fixed paraffin embedded (FFPE) biopsy and autopsy liver tissue samples of neonates with biliary atresia were evaluated. The molecular prevalence of these viral infections was assayed by different PCR and RT-PCR methods. The antigenic prevalence of HBV, HCV, and HCMV infections was also studied in these liver tissue samples by immunohistochemistry (IHC) method. HBV, HCV, and adenovirus genomes were detected in 9%, 6%, and 6% of liver autopsy and biopsy tissues of infants with biliary atresia, respectively. HBV and HCV co-infection was confirmed in 6% of FFPE samples. The genome of other investigated viruses was not detected in FFPE liver tissues. Detection of viral infection in FFPE liver tissue samples of newborns with biliary atresia, suggests the need for complete studies for the determination of accurate role of these viral infections in pathogenesis of biliary atresia.

Comparison of the Expression of Cell Adhesion Molecule Markers (E-Cadherin and Syndecan-1) between Young and Older Age Patients with Gastric Carcinoma.

AIM: The aim of this study was to evaluate the relationship between age and cell adhesion molecule markers (E-cadherin and syndecan-1). MATERIALS AND METHODS: Forty-three cases of gastric carcinoma below the age of 50 were referred to our center in the period of 5 years (2003­2008). Forty-three gastric carcinoma above the age of 50 years were sex-matched with the first group. Expression of syndecan-1 and E-cadherin were evaluated by immunohistochemistry in a total of 86 gastric carcinomas accompanying with all the clinicopathological findings in each case. RESULTS: The expression of syndecan-1 and E-cadherin did not show significant difference between two age groups; in addition, there were no significant differences in all the clinicopathological findings in these two age groups. DISCUSSION: Gastric carcinoma in young and old age adults showed no significant difference in respect of the expression of cell adhesion molecule markers. Our result shows that young age alone cannot be predictive of more metastasis and invasion potential.

Assessing the interstitial cells of Cajal, cells of enteric nervous system and neurotransmitters in slow transit constipation, using immunohistochemistry for CD117, PGP9.5 and serotonin.

BACKGROUND/AIMS: Slow transit constipation is one of the common causes of chronic constipation, in which the intestinal diameter is normal, but its transit time is markedly increased. The underlying cause in this disease is not definitely understood. METHODOLOGY: In this study was investigated the difference in the quantity of pace maker cells, cells of enteric nervous system and serotonin positive cells in normal colon and colon of the patients with slow transit constipation by using immunohistochemistry for c-Kit, PGP 9.5 and serotonin. RESULTS: The number of c-Kit positive pacemaker cells in the muscular layer was significantly decreased in the patients with slow transit constipation. PGP 9.5 positive enteric nervous system cells were significantly decreased in the patients with slow transit constipation in inner circular layer. Number of serotonin positive cells in the patients with slow transit constipation was significantly increased. CONCLUSIONS: Slow transit constipation is most probably a true enteric neuropathy.

Useful markers for differential diagnosis of oncocytoma, chromophobe renal cell carcinoma and conventional renal cell carcinoma.

Renal oncocytoma, conventional RCC (granular cell type) and chromophobe RCC have different prognosis. Sometimes differentiation between them is difficult in HandE slides. In a 5-year study of 128 renal tumors, we selected 76 cases [30 conventional RCC (CRCC), 16 papillary RCC, 21 chromophobe RCC (ChRCC), 8 oncocytoma, 1 collecting duct carcinoma (cdc)] and staining with Hale's colloidal iron, CK7, CK8, CK18, CK19, CK20, Vimentin, EMA, CD10 and RCC marker were done. No significant difference was seen between renal tumor subtypes with CK8, CK18, CK19, CK20 and EMA. The most useful markers were Vimentin, CK7, CD10, RCC marker and Hale's colloidal iron. Hale's colloidal iron staining with diffuse reticular fine cytoplasmic pattern was present in ChRCCs, but was absent in other subtypes and oncocytomas. Vimentin, CK7, CD10, RCC marker and Hale's colloidal iron can be used for the differential diagnosis of problematic epithelial tumors of kidney (CRCC, ChRCC and oncocytoma) - i.e. ChRCC: Vimentin, CD10 and RCC marker - negative, CK7 - positive and positive diffuse fine reticular cytoplasmic pattern of Hale's colloidal iron; oncocytoma: Vimentin, CK7, RCC marker and CD10 - negative and Hale's colloidal iron - negative; CRCC: CK7 - negative, Vimentin, CD10 and RCC marker - positive and Hale's colloidal iron - negative.

A nested PCR method for the identification of hepatitis B virus genotype in paraffin blocks of formalin-fixed liver biopsies.

Hepatitis B virus is a hepatotropic virus that causes acute and chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma; it is responsible for more than one million deaths annually worldwide despite hepatitis B vaccination. Until now, there are eight known genotypes (A-H).Clinical course of chronic hepatitis B varies according to the genotype of Hepatitis B virus. Liver biopsy becomes necessary to judge the degree of liver lesions and to make the final diagnosis, especially to make the diagnosis for latent liver damage and early-compensated cirrhosis. Genotype is very important for prognostication, but it has not yet been reported on liver tissues. Sometimes, it can be helpful to do genotyping of Hepatitis B virus of the liver tissue; such conditions include research programs, when serum is not available or when serum is negative for Hepatitis B virus DNA. In this study, we wanted to evaluate the feasibility of a simple method for genotyping of liver tissue samples. We performed genotyping of the liver biopsies and intended to find out a simple and reliable method for genotyping in the paraffin- embedded formalin- fixed liver tissue.Genotype D was the only isolated genotype in all the liver biopsies. The tissue genotype was just the same as that found in serum. The procedure was easy and good for large scale studies.Genotyping in the paraffin-embedded formalin-fixed stored liver tissue can be done with the same accuracy of the serum.

Hepatitis B virus genotypes in southwest Iran: molecular, serological and clinical outcomes.

AIM: To investigate the associations of hepatitis B virus (HBV) genotype with HBeAg and anti-HBe status, alanine aminotransferase (ALT) levels and HBV-DNA detection in different groups of HBV-infected patients in southwest Iran. METHODS: A total of 89 HBsAg-positive serum samples were collected from the same number of patients. All sera were then investigated to determine HBV DNA and serological markers. For all the polymerase chain reaction (PCR)-positive samples, biochemical, histopathological assays and genotyping were also performed. RESULTS: Genotype D was the only type of HBV found in different clinical forms of acute and chronic infections. There was a high prevalence of HBeAg-negative HBV-infected patients with chronic hepatitis (52.7%). Out of 55 patients with chronic hepatitis, seven (12.7%) were diagnosed with cirrhosis. A significant association between the presence of anti-HBe antibody and an increase in ALT level, among either HBeAg-negative (P = 0.01) or HBeAg-positive (P = 0.026) patients, was demonstrated. No significant differences were observed between the clinical outcomes of HBeAg-positive and -negative individuals (P = 0.24). CONCLUSION: Genotype D has been recognized as the only type of HBV found in different clinical forms of HBV infections, including cirrhosis, among the residents of southwest Iran. Anti-HBe possibly plays a role in disease progression in some patients with chronic hepatitis, at least for a period of disease.

Histologic differentiation of hepatocellular carcinoma from adenocarcinoma by a simple panel: evaluation of the pitfalls.

The histological differentiation of Hepatocellular carcinoma (HCC) from cholangiocarcinoma (CC) and metastatic adenocarcinoma (MA) of the liver is difficult in some cases and immunohistochemistry (IHC) is necessary for the diagnosis. HepPar-1 is a recently available antibody which seems to be very specific and sensitive for the diagnosis of HCC. MOC31 is an antibody directed against a cell surface glycoprotein and has been shown to be helpful in distinguishing between HCC and CC or MA as a negative marker in HCC. In this study we tried to apply these two markers for the diagnosis of HCC cases as a simple, useful and reliable panel. We selected 101 liver tumors which had proven diagnosis by several antibodies and cilinicopathologic correlation. The tumors with confirmed histologic diagnosis including 35 HCC, 58 MA, 7 CC and 1 combined HCC-CC.. HepPar-1 was positive in 30 of 35 cases of HCC; none of the other tumors were reactive for HepPar1 except for a case of metastatic gall bladder adenocarcinoma which showed areas of hepatoid differentiation in the H&E slides. MOC31 was positive in 5 of the HCC cases and stained 60 of 65 cases of MA. There were 4 cases of HCC with clear cell morphology, in most of which, IHC pattern was not diagnostic and further investigation was needed. As a conclusion the combination of positive Hepar1 and negative MOC31 is highly suggestive for HCC except for the clear cell variant. These two reliable markers are recommended for the initial step of differential diagnosis between HCC and MA and for the confirmation of the histologic diagnosis.