A Comparative Immunohistochemical Expression of TRAP in Odontogenic Cysts.

Introduction: Tartrate-resistant acid phosphatase (TRAP) is an acid phosphatase metalloprotein enzyme expressed in osteoclasts and is related to bone resorption. The molecular mechanisms involved in the different behavior of odontogenic keratocysts have not yet been fully elucidated. The purpose of this study was to compare TRAP expression in odontogenic keratocysts, radicular cysts, and dentigerous cysts. Materials and Methods: In this cross-sectional study, we selected 60 samples, including 20 cases of each one of the odontogenic keratocysts (OKC), radicular cysts (RC) and dentigerous cysts (DC). The samples were stained with TRAP monoclonal antibodies using immunohistochemistry. The data were analyzed using the Chi-Square and Kruskal-Wallis tests. Results: In this study, TRAP expression was observed in the lining epithelium of 50% of OKC cases and 5% of RC cases, while it was negative in the lining epithelium of DC. This difference was statistically significant (p<0.001). Moreover, the TRAP staining intensity in the lining epithelium had a significant difference between the groups (P<0.001). TRAP expression in the connective tissue of OKC, RC, and DC was positive in 35%, 30%, and 20% of the cases, respectively. This difference was not statistically significant (P=0.788). Also, staining intensity of TRAP-positive cells in the connective tissue of the lesions was not significant (P=0.634). Conclusion: In this study, we found a higher expression of TRAP in the lining epithelium of OKC, which may be one of the reasons for the aggressive behavior of OKC compared to other cysts. This finding supports the classification of OKC as an odontogenic tumor.

A Comparative Evaluation of the Genotoxic Effects of Mobile Phone Radiation Using Buccal Micronucleus Assay.

Statement of the Problem: Mobile usage has increased worldwide over the past two decades. There are conflicting reports about the carcinogenic effects of cell phone radiation on the oral mucosa. Micronucleus (MN) is considered a reliable marker for genotoxic damage. Purpose: This study aimed to identify the impact of mobile phone radiation on the MN frequency in oral mucosal cells. Materials and Method: In this descriptive-analytical study, 50 mobile phone users between the age group of 20-38 years were included. Samples were obtained from the right and left cheek mucosa of each subject (a total 100 cell samples). Every participant filled out a questionnaire about his or her cell phone usage habits. Additionally, personal information such as age, gender, and body mass index (BMI) were assessed. The Feulgen and Papanicolaou staining methods were used for staining of the cell samples. A total of 1000 cells in each sample were evaluated for MNs. Results: The mean number of MN in exposed and non-exposed mucosa by Feulgen method was 0.71±1.13 and 0.57±1.36, respectively. Also in Papanicolaou staining, the mean number of MN in the exposed mucosa and non-exposed mucosa was 6.94±6.61 and 6.54±6.88, respectively, but these differences were not significant (p> 0.05). The frequency of MN in non-specific DNA staining was significantly (5- to 6-fold) higher than DNA-specific staining. We observed no statically significant differences between MN frequency according to age, gender, BMI, and other cell phone usage habits (p> 0.05). Conclusion: This study showed that cell phone use does not cause genotoxic effects in the buccal mucosa in the oral cavity. Moreover, using non-specific DNA staining methods can increase the frequency of MN by more than 5- to 6-fold.

Immunohistochemical Expression of Epithelial Mesenchymal Transition Proteins in Squamous Cell Carcinoma of the Oral Cavity.

BACKGROUND & OBJECTIVE: Epithelial-Mesenchymal transition (EMT) is known to be a possible mechanism in tumor progression; however, there is insufficient evidence to support the contribution of this process in human cancers. The present study aimed to evaluate the expression of EMT markers in normal oral epithelium and oral squamous cell carcinoma and also correlates with some clinicopathological parameters. METHODS: This study was conducted on 70 samples, including 20 cases of normal epithelium and 50 cases of Oral Squamous cell Carcinoma (OSCC). To examine the expression level of these proteins, immunohistochemical staining was performed for samples using E-cadherin and N-cadherin monoclonal antibodies. RESULTS: Reduced expression of E-cadherin was observed in 74% of OSCC and 15% of normal epithelium samples; this difference was statistically significant (P˂0.000). With the progression of SCC from well towards poor differentiation, the E-cadherin expression decreased; however, this difference was not statistically significant (P=0.642). Normal epithelial specimens were negative for N-cadherin expression in 75% of cases, whereas OSCC specimens showed high expression of N-cadherin in 46% of cases, this difference was statistically significant (P=0.01). Although 62.5% of poorly differentiated OSCC showed high expression of N-cadherin, the difference between the histopathological grades was not significant (P=0.586). No significant relationship was found between markers expression and patient's age, gender, and tumor location. CONCLUSION: This study showed that OSCC tissues showed high EMT phenotype (reduced E-cadherin expression and high expression of N-cadherin) compared to normal oral mucosa which may indicate the possible key role of EMT mechanism during oral carcinogenesis.

Cytomorphometric Assessment of Buccal Mucosa Cells and Blood Sugar Status in Diabetic Patients in Zahedan (2019).

Background: Diabetes mellitus is one of the major global health threats. Diabetes can cause adverse cytopathological changes in cells and predispose them to pathological lesions. The present study aimed to investigate the cytopathological changes of oral mucosal cells in type 1 and 2 diabetes patients and its relationship with blood sugar status. Methods: This study descriptive-analytical was performed on 40 type-1 diabetes patients, 40 type-2 diabetic patients, and 20 non-diabetic individuals (control group) with simple sampling in Zahedan (2019). Their buccal mucosa was sampled by a cytobrush and the microscope slides were prepared with Papanicolaou staining. The nuclear and cytoplasmic area and cytoplasmic-nuclear ratio were calculated. Furthermore, the relationship of hemoglobin A1C and fasting blood sugar with these parameters were also examined. Data was analyzed with one-way-ANOVA, Kruskal-Wallis, Post Hoc Tukey, Mann-Whitney, Pearson correlation and Spearman correlation tests. In this regard, the statistical software SPSS (version 21) was used and a p-value <0.05 was considered statistically significant. Results: Based on the findings, only the nuclear area was significantly larger in type 1 and type 2 diabetes patients, compared to the control group (p<0.001 and p=0.010), respectively. Moreover, the comparison of cytomorphometric changes between type 1 and type 2 diabetes patients did not show a significant difference. In addition, the hemoglobin A1C levels were merely associated with the cytoplasmic area in type 2 diabetes patients (p=0.011), while fasting blood sugar levels were not associated with any of the parameters in type 1 and type 2 diabetes patients (p>0.050). Conclusion: Diabetes, as an independent factor, can cause cytomorphometric changes in the buccal mucosal cells of type 1 and type 2 diabetes patients. It seems that the type of diabetes does not affect these changes. hemoglobin A1C levels were correlated with cytoplasmic area in type 2 diabetes patients.

Role of EGFR gene polymorphisms in oral squamous cell carcinoma patients of Southeast Iran: A case-control study.

BACKGROUND: The decisive etiology of oral squamous cell carcinoma (OSCC) is still ambiguous, but we recognize the contribution of genetic aberration and environmental agents due to OSCC initiation. In the current study, we elucidate the potential impact of EGFR gene polymorphisms on the risk of OSCC in Southeast Iran. METHODS: Forty-eight OSCC patients along with 100 healthy volunteers were included. Three polymorphisms of the EGFR gene (rs2227983, rs2293347 and rs2227984) were genotype by Tetra-ARMS PCR. Data were analyzed with a chi-square test, and p<0.05 was considered significant. RESULTS: In rs2227983, the frequency of AG and GG genotypes were 62.5%, 37.5% in cases and 42%, 57% in the control group (P=0.02, OR=2.3) and also A allele frequency was 31.3% in the case and 22% in control (P=0.08, OR=0.62). AG + AA genotype frequency was 62.5% and 43% in case and control, respectively (p=0.03, OR=2.2). In rs2227984 and rs2293347, no statistical differences showed in the distribution of genotypes between the case and control group. Also the majority of the OSCC belonged to grade I (43.8%). CONCLUSION: The present investigation indicated that rs2227983 polymorphism might contribute to OSCC susceptibility in Iran's southeast population. Although, with the inconsistent interpretation mentioned due to the various geographical residencies and populations, more studies of significant populations are suggested to validate our findings.

Association of Glutathione-S-Transferases M1 and T1 Deletional Variants with Development of Oral Squamous Cell Carcinoma: A Study in the South-East of Iran.

Background: The role of genetic polymorphisms in genes of Glutathione-S-transferases (GST) enzymes in susceptibility to oral cavity cancers is controversial. Oral Squamous Cell Carcinoma (OSCC) is the most common oral cavity neoplasm. Aimed to evaluate the potential impacts of two well-known null variants residing in the gene encoding GSTM1 and GSTT1 enzymes of OSCC patients in the southeast of Iran. Methods: In a case-control design, 113 individuals (50 OSCC patients, and 63 healthy subjects) were included. DNA was extracted using paraffin-embedded tissues. GST genotyping was carried out using multiplex PCR. Results: In 113 participants, 41 (36.3%) and 72 (63.7%) were males and females respectively. No significant difference was recognized for distribution of GSTM1 (P=0.11) and GSTT1 (P=0.28) null genotypes between OSCC patients (58%, and 24% respectively) and healthy controls (42.9% and 15.9% respectively). Also, no significant difference was noted regarding the frequency of GSTM1 null genotype in different histological grades, however, those patients with more aggressive disease (poorly differentiated or grade III) revealed with a significantly higher ratio (66.7%) of GSTT1 null genotype (P=0.002). The highest odds ratio for OSCC was related to combined null genotypes for GSTM1 and GSTT1 (OR=2.5, 95% CI: 0.7-9.2), however, this was not statistically significant finding (P=0.15). Conclusion: Null genotypes polymorphisms were more common in OSCC than healthy individuals. GSTT1 null genotype may be an important genetic factor in the progression of OSCC.

Dental Health Status of HIV-Positive Patients and Related Variables in Southeast Iran.

BACKGROUND: Different factors can be responsible for the increased prevalence of dental caries and missing teeth in HIV-positive patients. OBJECTIVES: This study evaluates dental health status and its relationship with social, behavioral, and medical factors in HIV-positive patients under the coverage of Zahedan University of Medical Sciences in Southeast Iran. PATIENTS AND METHODS: In a cross-sectional study, the dental health status of 119 HIV-positive patients was assessed in accordance with WHO indices and included decayed, missing, and filled teeth (DMFT). A questionnaire on different social, behavioral, and medical variables was filled out for every case and the relationship and correlation of the variables to dental health status were investigated using One-way ANOVA, the Kruskal Wallis test, the t-test, the Mann-Whitney test, Spearman's rho correlation coefficient, and Pearson correlation. RESULTS: The mean value of DMFT index was 11.87 ± 8.08, where the mean values of decayed and missing teeth were 8.42 ± 5.44 and 3.43 ± 4.07, respectively. DMFT index, decayed, and missing teeth correlated only with age (P < 0.0001, P = 0.009, P < 0.0001) and duration of HIV involvement (P = 0.004, P = 0.031, P = 0.007). CONCLUSIONS: The dental health status of HIV-positive patients in this region was almost inappropriate. Most social, behavioral, and medical factors had no influence on dental health; only a correlation between dental health, age, and duration of HIV involvement was observed.

Differential immunohistochemical expression of matrix metalloproteinase-10 (MMP-10) in non-melanoma skin cancers of the head and neck.

Basal Cell Carcinoma (BCC) and Squamous Cell Carcinoma (SCC) are two common skin malignancies with different potentials for invasion and metastasis. The mechanism responsible for various growth patterns observed in SCC and BCC is still not fully understood. The aim of this study was to investigate the expression of matrix metalloproteinase-10 in non-melanoma skin cancers, including BCC and SCC of the head and neck. The study group consisted of 60 specimens, including 30 BCC and 30 cutaneous SCC of the head and neck. Sections of tumor biopsy samples were immunohistochemically examined for the expression of MMP-10. Data were analyzed by SPSS (V.21) using Mann-Whitney and Kruskal Wallis tests. We found higher immunohistochemical expression of MMP-10 in tumor epithelium and stroma of SCC as compared with BCC. However, this difference was significant only in tumor epithelium (P=0.000). Moreover, the level of MMP-10 expression in tumor epithelium of grades III and II of SCC was significantly greater compared to grade I tumors (P<0.05).Our results suggest that the level of the MMP-10 expression in tumor epithelium of cutaneous SCC and BCC may contribute to the different invasive patterns observed in these tumors. Also, the expression of MMP-10 is associated with tumor differentiation in cutaneous HNSCC.

Comparative Study of Mast Cell Count in Oral Reactive Lesions and Its Association with Inflammation.

OBJECTIVE: Reactive hyperplastic lesions are one of the most common lesions of the oral cavity. Mast cells can be found in various oral lesions. However, the exact role of mast cells in oral reactive lesions is not fully understood. The aim of this study was to compare the mast cells count in various oral reactive lesions and to evaluate the correlation between the mast cells number and the intensity of inflammation. MATERIAL AND METHOD: This cross-sectional study was performed on 80 samples of oral reactive lesions including irritation fibroma, pyogenic granuloma, peripheral giant cell granuloma and peripheral ossifying fibroma (20 for each). Eight samples of normal oral mucosa were selected as the control group. To determine the mast cells count and the intensity of inflammation, Toluidine blue and Hematoxylin & Eosin staining was performed respectively. The data was analyzed with SPSS (V.21), Kruskal-Wallis, Tukey and Spearman's correlation coefficient tests. RESULTS: In this study, a significant increase in mast cells count was found in oral reactive lesions compared to normal oral mucosa (p < 0.001). Difference of mast cell count between irritation fibroma and the peripheral giant cell granuloma groups (p=0.023), peripheral ossifying fibroma and peripheral giant cell granuloma groups (p=0.001) was statistically significant. There was a significant correlation between mast cell count and the intensity of inflammation in the irritation fibroma and pyogenic granuloma groups. CONCLUSION: The finding of this study showed that mast cells count in peripheral ossifying fibroma and irritation fibroma were significantly higher than normal oral mucosa, so mast cells may have some role in the induction of fibrosis in oral reactive lesions.

Methylenetetrahydrofolate reductase C677T and A1298C gene polymorphisms in oral squamous cell carcinoma in south-east Iran.

BACKGROUND: Methylenetetrahydrofolate reductase (MTHFR) gene encodes an essential enzyme involving in folate metabolism. Due to the role of folate in DNA integrity, polymorphisms of MTHFR are interesting targets for cancer risk studies. Our goal was to evaluate the prevalence of MTHFR C677T and A1298T single nucleotide polymorphisms in oral squamous cell carcinoma (OSCC). METHODS: The study was conducted on 57 OSCC patients diagnosed within 2004-2013 along with 62 non-OSCC subjects. DNA was extracted by standard kit protocol. Subsequently, tetra-ARMS (amplification refractory mutation system)-PCR was applied to identify the selected polymorphisms. RESULTS: Data showed that CT and TT genotypes of C677T polymorphisms significantly increased the risk of OSCC [odds ratio (OR) = 2.2, 95% CI: 1-5, P = 0.04]. Although allelic distribution was not significantly different between patients and controls, T allele of C677T polymorphism was closely associated with the risk of OSCC (OR = 2.5; 95% CI: 0.9-6.9; P = 0.07). Results indicated that C677T/A1298C: CC/AC and C677T/A1298C: CC/AA haplotypes were the most common combinations in OSCC patient and control groups, respectively. (OR = 1.5, 95% CI: 0.6-3.8, P > 0.05). CONCLUSION: Our results highlight the possible impact of C677T polymorphism in increasing the risk of OSCC development.

Protein Expression of Stromelysin-2 in Head and Neck Squamous Cell Carcinomas.

BACKGROUND: Some matrix metalloproteinases (MMPs) are involved in invasion and metastasis of head and neck squamous cell carcinoma (HNSCC). However, there are few studies on association between stromelysin-2 (ST-2) and invasive behavior of HNSCC. The purpose of this study was to investigate Stromelysin-2 expression by immunohistochemistry. MATERIALS AND METHODS: This study was conducted on 81 specimens, including 61 HNSCC and 20 non neoplastic epithelium. Sections with 5 micron thickness were prepared and stained with immunohistochemistry technique. Then expression of ST-2 was evaluated according to percentage of stained cells and intensity of staining. Data were analyzed by SPSS (V.21) using Kruskal-Wallis and Tukey tests (P<0.05). RESULTS: The 61 HNSCC specimens were grades I 36.1%, II 34.4% and III 29.5%. The level of ST-2 expressions were moderate (++) and intensive (+++) in 21.3% and 78.7% of tumors, respectively. The ST-2 expression level was only significant between the tumors with grade I and grade III (P=0.016). Tumors presented ST-2 expression with staining intensity of mild 6.6%, moderate 26.2% and strong 67.2%. Staining intensity of ST-2 in grade I tumors was significantly lower than grade II and grade III (P<0.05), and there was no significant difference between grades II and III (P=0.99). CONCLUSIONS: According to this study, the expression of ST-2 is associated with histopathological grade and tumor differentiation in HNSCCs.

Human Cytomegalovirus in Oral Squamous Cell Carcinoma in Southeast of Iran.

BACKGROUND: Carcinogenesis is a multi-step process and the role of infectious agents in this progression has not been fully identified. Since human cytomegalovirus (HCMV) is frequently presented in the gingival sulcus fluid, we hypothesized that this virus would be important in the pathogenesis of oral squamous cell carcinoma (OSCC). OBJECTIVES: The aim of this study was to investigate the presence of active HCMV in different histopathological grades of OSCC in southeast of Iran. MATERIALS AND METHODS: Forty eight individual specimens were evaluated in this study. Serial sections were obtained from paraffin-embedded tissue samples of OSCC biopsies. The frequency of HCMV was investigated using the real-time polymerase change reaction method after DNA extraction from biopsies. RESULTS: The mean age of the patients (66.7% female and 33.3% male) was 58.6 years. Only three cases (6.3%) of the grade I, OSCC biopsies, were positive for active HCMV with average load of 57.7 × 10(3). CONCLUSIONS: According to the low prevalence of HCMV in OSCC, it seems that this virus plays a minor role in this kind of cancer at least in southeast of Iran. More comprehensive studies are needed to investigate the oncomodulatory effect of this virus on OSCC.

Expression of Matrix Metalloproteinase-10 at Invasive Front of Squamous Cell Carcinoma and Verrucous Carcinoma in the Oral Cavity.

BACKGROUND: Matrix metalloproteinases (MMPs) are a family of zinc metalloproteinases capable of degrading components of connective tissues. MMP-10 is frequently expressed in human cancers. The aim of this study was to immunohistochemically evaluate its expression in oral squamous cell carcinoma (OSCC) and verrucous carcinoma (OVC). MATERIALS AND METHODS: A retrospective analysis of 73 samples (31 OSCC, 22 OVC and 20 non-neoplastic epithelium) was performed. All samples were immunohistochemically stained with monoclonal MMP-10 antibody and expression levels and staining intensity were evaluated with respect to microscopic features. Data were analyzed by SPSS (V.21), Mann-Whitney and Kruskal Wallis tests. RESULTS: MMP-10 was detected in all OSCC and OVC cases. The expression of MMP-10 in OSCC was intensive (score 3) and in OVC was low and moderate (score 1 and score 2) more frequently. Non- neoplastic epithelium did not show MMP-10 expression. Differences between groups was statistically significant (p<0.05). However, the expression of MMP- 10 was not obviously different between various grades of OSCC. CONCLUSIONS: According to our study, MMP-10 protein can be important possible factor in the transformation of normal oral epithelium to OVC and OSCC, also the level of MMP-10 expression at invasion front of the lesions can be helpful in the differentiation of OVC and OSCC.

Reactive hyperplastic lesions of the oral cavity.

INTRODUCTION: Peripheral reactive lesions of soft tissue are common oral lesions that dentists face during routine examinations. Diagnosis and development of a treatment plan is difficult if dentists are not aware of the prevalence and clinical symptoms of these lesions. The frequency of these lesions differs across various populations. The aim of this study was to determine the frequency and distribution of oral reactive lesions over a period of 7 years (2006-2012). MATERIALS AND METHODS: In this retrospective study, available records from the archives of the Department of Pathology, Dental School and the two main hospitals in southeast of Iran (Zahedan) over a period of 7 years (2006-2012) were reviewed. Information relating to the type of reactive lesion, age, gender and location was extracted and recorded on data forms. Data were analyzed using SPSS statistical software (V.18) using the chi-square and Fisher's exact test. RESULTS: Of 451 oral lesions, 91 cases (20.2%) were reactive hyperplastic lesions. The most common lesions were pyogenic granuloma and irritation fibroma, respectively. These lesions were more frequent in women (60%) than men (40%). The most common locations of involvement were the gingiva and alveolar mucosa of the mandible, and lesions were more common in the 21-40-year age group. The relationship between age group and reactive lesions was statistically significant (P=0.01). CONCLUSION: The major findings in this study are broadly similar to the results of previous studies, with differences observed in some cases. However, knowledge of the frequency and distribution of these lesions is beneficial when establishing a diagnosis and treatment plan in clinical practice.

Immunohistochemical Assessment of HER3 Expression in Odontogenic Cysts.

BACKGROUND: It has been demonstrated that HER3 plays an important role in some human cancers and the HER3 expression is associated with worse survival in solid tumors. OBJECTIVES: This study was conducted to compare HER3 expression in epithelial lining of radicular cysts (RCs), dentigerous cysts (DCs) and odontogenic keratocysts (OKCs). MATERIALS AND METHODS: This was a descriptive-analytical study, which assessed all 57 paraffin blocks of RCs, DCs and OKCs (21 RCs, 16 DCs, 20 OKC) from pathological archive of Dentistry College of Zahedan, Iran. The HER3 expression in cytoplasm and membrane was examined by immunohistochemical method. The data collected was analyzed using SPSS16 by ANOVA and Chi-square. P < 0.05 was considered as statistically significant. RESULTS: The HER3 expression had positive results in 52.4% of OKC, 50% of DC and only 20% of RC samples. There was a significant difference between HER3 expression in OKCs and RCs. CONCLUSIONS: The HER3 expression in developmental odontogenic cysts was higher than that in inflammatory odontogenic cysts. The higher rate of HER3 expression in OKC may justify inherent growth potential, stimulation-independent proliferation capability, invasive growth and high recurrence rate of the cyst accepted today as a tumor.

Human herpesvirus-6 and epstein-barr virus infections at different histopathological grades of oral squamous cell carcinomas.

BACKGROUND: The aim of this study was to determine the prevalence and viral load of Epstein-Barr virus (EBV) and Human herpesvirus-6 (HHV-6) in different histopathologic grades of oral squamous cell carcinoma (OSCC). METHODS: Forty-five formalin-fixed paraffin-embedded tissue section of OSCC patients were analyzed by quantitative real-time polymerase chain reaction for detection of EBV and HHV-6. RESULTS: The mean age of the patients was 58.6 years, 69% of whom were female, and 31% were male. Overall, the positive rate for EBV and HHV-6 were 16.7% and 27.1%, respectively; and the mean viral load EBV was 27.9 × 10(3) and 38.5 × 10(3) for HHV-6. No correlation was demonstrated between the viral load of EBV DNA (P = 0.35) and HHV-6 (P = 0.38) at the different OSCC histopathologic grades. CONCLUSIONS: These findings neither lend support to the hypothesis that EBV and HHV-6 are directly involved in OSCC nor rule out the possibility that these viruses play an indirect role in carcinogenesis in this area.

Immunohistochemical correlation of epidermal growth factor receptor and c-erbB-2 with histopathologic grading of mucoepidermoid carcinoma.

OBJECTIVE: Mucoepidermoid carcinoma is the most common salivary gland malignancy with highly variable biologic potential that correlates with the histopathologic grade of the tumor. Therefore, identification of the histopathologic grade of the mucoepidermoid carcinoma is very important in the treatment and determination of the final prognosis. The present study was performed to survey immunohistochemically Epidermal Growth Factor ReceptorEGFR and c-erbB-2 expression in different grades of mucoepidermoid carcinoma. MATERIALS AND METHODS: This retrospective study included 46 formalin-fixed, paraffin-embedded blocks of mucoepidermoid carcinoma. Based on histopathologic parameters, samples were classified into three grades. Then new sections were made and stained by immunohistochemistry (IHC) method for EGFR and c-erbB-2. Finally, EGFR and c-erbB-2 expression and their correlation with histopathologic grading were statistically analyzed by ANOVA. Nineteen samples of normal salivary gland tissue were also chosen as control group. RESULTS: The means of EGFR and c-erbB-2 were 71%, 71%, respectively. Statistically significant correlation was found between EGFR expression and histopathologic grading of mucoepidermoid carcinoma of salivary glands (P < 0.001). There was no statistically significant correlation between histopathologic grading of salivary gland mucoepidermoid carcinoma and c-erbB-2 expression (P = 0.60). CONCLUSION: There is a parallelism between an increase in EGFR expression and increase in the histopathologic grading of salivary gland mucoepidermoid carcinoma. Therefore, the biologic behavior of salivary gland mucoepidermoid carcinoma can be determined by EGFR expression and it is a useful technique for determination of tumor grades and probably their prognosis.