Immunohistochemical analysis of proliferating cell nuclear antigen and minichromosome maintenance complex component 7 in benign and malignant salivary gland tumors.

Background: Proliferation markers have been used to determine the behavior and prognosis of benign and malignant tumors; this study was aimed to compare the immunohistochemical (IHC) expression of proliferating cell nuclear antigen (PCNA) and novel marker minichromosome maintenance complex component 7 (MCM7) in common salivary gland tumors including pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC), and adenoid cystic carcinoma (AdCC), to find a possible significant correlation between benign and malignant tumors. Materials and Methods: In this cross-sectional study, a total of 90 cases, including 30 PAs, 30 MECs, and 30 AdCCs, were collected. The IHC expressions of PCNA and MCM7 were evaluated. Their expressions were compared with each other and between benign and malignant tumors. Statistical analysis was performed by Chi-square and Tukey's test. P value was considered 0.05. Results: Out of 30 cases of PA, 28 cases (93.3%) were PCNA positive and 28 cases (93.3%) were MCM7 positive. In the AdCC cases, 29 cases (96.6%) were PCNA positive and 29 cases (96.6%) were MCM7 positive. In the MEC cases, all cases (100%) were PCNA positive and 23 cases (76.6%) were MCM7 positive. The labeling index (LI) of MCM7 and PCNA was evaluated, and this index was lower in MCM7 LI than PCNA in all tumors. The MCM7 and PCNA expression showed a significant difference in PA and MEC (P < 0.001). Conclusion: PCNA expression was higher than MCM7 expression in salivary gland tumors. However, more studies are needed to evaluate the malignant activity of these tumors with group of markers such as MCM family members.

Mel-CAM Expression in Common Oral Carcinomas.

STATEMENT OF THE PROBLEM: Mel-CAM (CD146, MUC18) is a 113-kD heterophilic cell-cell adhesion glycoprotein found in normal and tumoral tissues. The biologic functions and role of the Mel-CAM can be employed as a diagnostic marker in pathology. PURPOSE: The aim of this study was assessing the expression of Mel-CAM in common oral carcinomas like salivary gland mucoepidermoid carcinoma (MEC) and oral squamous cell carcinoma (OSCC) to differentiate the OSCC from high-grade MEC. MATERIALS AND METHOD: This study was performed on 19 specimens of MEC and 17 specimens of OSCC, which were retrieved from the archive of Department of Pathology of Taleghani Hospital, Tehran, Iran. Immunohistochemical staining was performed by using antibody against CD146. The data were analyzed using SPSS software through Mann-Whitney, Spearman's correlation coefficient, and Kruskal-Wallis tests. RESULTS: Mel-CAM was expressed in all MEC samples and 10 OSCC cases. The two groups were significantly different regarding the CD146 expression (p= 0.035). Furthermore, the CD146 expression was found to be significantly correlated with the invasion mode (p= 0.002), tumor size (p= 0.012), and histological grade (p= 0.024) in OSCC group. No significant correlation existed between the expression, intensity, and location with the histological grade of MEC (p> 0.05) nor was any significant correlation detected between the CD146 expression and lymph node metastasis in neither group. CONCLUSION: Regarding the significant correlation between the CD146 expression and the prognostic factors in OSCC, this marker may predict the prognosis in OSCC patients, but not the MEC lesions. It cannot be used for differentiating high-grade MEC and OSCC.

Comparative Analysis of P63, Maspin and Matrix Metalloproteinase 2 Expression in Mucoepidermoid Carcinoma and Adenoid Cystic Carcinoma of Salivary Glands.

STATEMENT OF THE PROBLEM: The tumor suppressor role of myoepithelial cells and related mechanisms in breast tumors are well understood. However, the role of these cells in tumors of salivary glands is debatable. PURPOSE: The present study was designed to determine the expression of p63, mammary serine protease inhibitor (maspin) and matrix metalloproteinase 2 (MMP-2) in mucoepidermoid carcinoma (MEC) and adenoid cystic carcinoma (ADCC) of salivary glands due to various cellular differentiation and structure. The association between the expression of these markers and clinicopathologic features and myoepithelial differentiation were also evaluated. MATERIALS AND METHOD: P63, maspin, and MMP-2 expression were immunohistochemically studied in 67 cases including35 cases of MEC and 32 cases of ADCC. The smooth muscle actin (SMA) staining was also applied to confirm the presence of myoepithelial differentiation. Data was analyzed using Chi-square test, Mann-Whitney U test and t-test. RESULTS: The expression of p63 (p= 0.009) and maspin (p= 0.012) significantly differed between the study groups. P63 positive cells in MEC were negative for SMA staining in contrast to ADCC. Furthermore, the expression of P63 (p= 0.045) and maspin (p= 0.019) significantly and inversely correlated with histologic grade in ADCC. Likewise, positive significant correlation was detected between histologic grade and expression of P63 (p= 0.018) and MMP-2 (p= 0.003) in MEC samples. CONCLUSION: Our findings showed that MEC is devoid of myoepithelial cells. The difference in expression of P63 and maspin in ADCC and MEC highlighted the role and presence of myoepithelial cells in ADCC. Indeed, the high expression of P63 and maspin in well-differentiated ADCCs suggests the tumor suppressor effect of myoepithelial cells. Considering the association between the evaluated markers and histological grade, p63 in both tumors, maspin in ADCC and MMP-2 in MEC may be efficient predictors of clinical behavior.

Evaluation of VEGF expression correlates with COX-2 expression in pleomorphic adenoma, mucoepidermoid carcinoma and adenoid cystic carcinoma.

BACKGROUND: Pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC), and adenoid cystic carcinoma (AdCC) are the most common benign and malignant salivary gland tumors. Cyclooxygenase-2 (COX-2) is a key regulatory enzyme that its overexpression in various tumors is correlated with progression, metastasis, and apoptosis inhibition. Vascular endothelial growth factor (VEGF) is a potent angiogenic mediator that has an important role in neoplastic angiogenesis. The aim of this study was to immunohistochemically analyze the expression of COX-2 and VEGF and to compare the expression of benign and two malignant salivary gland tumors with varied structures. MATERIALS AND METHODS: In this cross-sectional study, 90 specimens including 30 cases of each tumor were retrieved. Immunohistochemical staining of COX-2 and VEGF was performed for all the samples. The percentage of positive tumor cells and staining intensity was evaluated by two pathologists blindly. Data were analyzed by Chi-square and Gamma test and P < 0.05. RESULTS: A statistically significant difference was noted between the expression and intensity of COX-2 and VEGF in PA, MEC, and AdCC (P < 0.05). A significant correlation was observed between COX-2 and VEGF expression in MEC and AdCC (P < 0.05). However, no significant correlation was found between the expression and intensity of COX-2 and VEGF with histologic grade and lymph node metastasis in MEC and AdCC (P < 0.05). CONCLUSION: High expression of VEGF and COX-2 in malignant tumors compared to PA suggested the role of both markers in malignant transformation. The significant correlation of VEGF expression with COX-2 may represent the role of COX-2 in tumor angiogenesis by modulating VEGF production.

Extra Skeletal Ewing's Sarcoma: a Case Report.

Ewing's sarcoma is an uncommon malignancy primarily affecting bone tissue and usually occurs in adolescents and young adults. This paper reports a rare case of extra-skeletal Ewing's sarcoma of the oral cavity soft tissue. In the clinical examination, a mass of 1.5×1.5cm in diameter was observed in the right mandibular vestibule. Radiographic examination revealed no involvement of mandible. Microscopically, the tumor was composed of malignant small round cell tumor that exhibited immunoreactivity for CD99. Enucleation surgery under local anesthesia was performed for the patient and prognosis was excellent. The patient remained symptom-free after 13 months of follow-up.

CD44 expression in pleomorphic adenoma, carcinoma ex pleomorphic adenoma and their adjacent normal salivary glands.

BACKGROUND: CD44 is a transmembranous proteoglycan, with a main role of cell adhesion to other cells and to extracellular matrix involved in the preservation of three-dimensional structure of organs. Pleomorphic adenoma (PA) is a common benign salivary gland tumor, composed of myoepithelial and ductal components. Carcinoma ex-PA (CXPA) is malignant transformation of the epithelial elements in PA. The aim of this study was to evaluate CD44 expression by immunohistochemistry in these two tumors and normal salivary gland near these tumors. MATERIALS AND METHODS: In this cross-sectional immunohistochemical study, 40 paraffin blocks (formalin fixed, paraffin embedded) with thirty belonging to PA and ten blocks of CXPA and 18 paraffinized blocks of normal salivary glands' tissue adjacent to tumoral tissue (13 in the vicinity of PA and 5 in the vicinity of CXPA) were selected. Immunohistochemical expression of CD44 was observed and compared with each other. For data analysis, we used Chi-square, Kruskal-Wallis, and Mann-Whitney tests and the quantity of P values was considered 0.05. RESULTS: There was a significant difference in CD44 expression frequency between PA, CXPA, and normal salivary glands with higher expression noted in CXPA. Furthermore, expression frequency of CD44 in adjacent normal salivary gland of CXPA was significantly higher than PA. There was no significant difference in the expression of CD44 with respect to lymph node metastasis. CONCLUSION: Higher expression of CD44 in CXPA might illustrate CD44's role in malignant transformation of PA.

CD20+ Tumor Infiltrating B Lymphocyte in Oral Squamous Cell Carcinoma: Correlation with Clinicopathologic Characteristics and Heat Shock Protein 70 Expression.

OBJECTIVE: B lymphocyte infiltration in the tumor microenvironment has been proposed to play pivotal roles in tumor progression. Heat shock protein 70 (HSP70) expressed by tumor cells can induce antitumor immune response. Few studies have examined the clinicopathologic relationship between tumor infiltrating B lymphocyte and HSP70 expression in human cancer. So far, there is no complete knowledge on the relationship in oral squamous cell carcinoma (OSCC). The present study was conducted to evaluate the relationship between tumor infiltrating B lymphocyte and HSP70 expression in OSCC, as well as the clinical outcome. MATERIALS AND METHODS: In this retrospective study, the immunohistochemical analysis of 50 OSCC specimens was performed using CD20 and HSP70 antibodies. The relationship between markers' expression and clinicopathologic data was evaluated using Mann-Whitney test, Chi-square test, logistic regression model, and Spearman's correlation coefficient. RESULTS: The data analysis showed significant correlation between peritumoral CD20+ B lymphocyte infiltration and lymph node metastasis (P = 0.047). Furthermore, HSP70 expression was significantly correlated with stage (P = 0.003), lymph node metastasis (P < 0.001), and tumor size (P = 0.044). However, no relationship was observed between B lymphocyte infiltration and HSP70 expression. CONCLUSION: The results suggest that peritumoral B lymphocyte infiltration and HSP70 expression level have significant association with OSCC and may be considered as prognostic indicators in OSCC. Thus, evaluation of B cells as therapeutic targets in OSCC patients is recommended.

Are CD68 and Factor VIII-RA Expression Different in Central and Peripheral Giant Cell Granuloma of Jaw: An Immunohistochemical Comparative Study.

OBJECTIVE: Central giant cell granuloma and peripheral giant cell granuloma of the jaw and oral cavity are identical in histopathologic features, although they are different in pathogenesis and clinical behavior. The aim of present study was to compare CD 68 and factor VIII related antigen (VIII-RA ) immunoreactivity in central giant cell granuloma and peripheral giant cell granuloma to determine the biologic nature and clinical behavior of these lesions which may lead to a better or new treatment modality. MATERIAL AND METHOD: CD68 and factor VIII-RA expression were examined immunohistochemically in 22 cases of central giant cell granuloma (10 aggressive and 12 non- aggressive ) and 19 cases of peripheral giant cell granuloma. The Kruskal-Wallis test followed by the Dunn test was used for data analysis. RESULTS: CD68 expression was observed in approximately 100% of multinucleated giant cells and 50% of mononuclear cells. Overexpression of factor VIII-RA in the endothelial cells of capillary like vessels in the periphery of the lesions was prominent. A statistical significant difference for CD68 intensity score in mononuclear cells among three groups (P=0.016) was observed. Indeed, factor VIII-RA intensity score in the endothelial cells of central giant cell granuloma and peripheral giant cell granuloma showed significant difference (P=0.004). CONCLUSION: These findings support the histiocyte/macrophage nature of multinucleated giant cells and mononuclear cells. Overexpression and high intensity score of CD68 in mononuclear cells and the high intensity score of factor VIII-RA in endothelial cells represent less aggressive behavior in central giant cell granuloma.

Orthokeratinized Odontogenic Cyst of the Maxilla: Report of a Case and Review of the Literature.

The orthokeratinized odontogenic cyst is a relatively rare developmental odontogenic cyst of the jaws that occurs predominantly in males between the third and fourth decades. According to the 2005 World Health Organization's classification, orthokeratinized odontogenic cyst is not a part of the keratocystic odontogenic tumor spectrum. We present a case of a 41-year-old male with a history of remarkable lingual expansion in the anterior part of the maxilla since last year with rapid growth in the last three months as a unilocular well-defined radiolucent lesion extending from maxillary left central incisor to the right second premolar. Orthokeratinized odontogenic cyst is a specific type of keratinized odontogenic cysts which is completely different from keratocystic odontogenic tumor from the viewpoint of the clinical and pathological features.

Combined Analysis of Vascular Endothelial Growth Factor Expression with Cyclooxygenase-2 and Mast Cell Density in Oral Squamous Cell Carcinoma.

BACKGROUND: Overexpression of vascular endothelial growth factor (VEGF) and cyclooxygenase-2 (COX-2) and increasing mast cell density (MCD) in premalignant and malignant oral lesions have been documented. However, their correlation with clinicopathologic parameters and survival rate in oral squamous cell carcinoma (OSCC) is not completely clear. This study aimed to assess these subjects. METHODS: VEGF, COX-2, and mast cell tryptase expression were examined immunohistochemically in 57 cases of OSCC. The relationships between the markers' expression and clinicopathologic data were assessed using bivariate and multivariate analysis. RESULTS: Spearman's rank correlation coefficient showed a significant correlation between VEGF and COX-2 expression (r = 0.462, p < 0.001), as well as between VEGF expression and MCD (r = 0.306, p < 0.001). Multivariate analysis showed no significant correlation between the markers' immunoexpression and overall survival (OS), but a significant correlation between mode of invasion and OS [hazard ratio 0.362 (95% CI: 0.138- 0.974); p = 0.038] was observed. An association between MCD and gender (p = 0.042) was also found, as MCD was higher in males. CONCLUSION: The significant correlation of VEGF expression with COX-2 expression and MCD may represent the roles of COX-2 and MCD in tumor angiogenesis by modulating VEGF production. However, VEGF, COX-2, and MCD are not useful indicators to predict prognosis in OSCC. Nevertheless, the mode of invasion can be considered as an independent prognostic factor in OSCC patients.

Multifocal epithelial hyperplasia: a forgotten condition in the elderly.

Multifocal epithelial hyperplasia (MEH), also known as focal epithelial hyperplasia and Heck disease, is a relatively rare condition caused by the human papillomavirus. This case report describes a 92-year-old man who presented with multiple, asymptomatic, circumscribed, soft, flattened papules in different sizes on the retrocommissure of his lower lip. The lesions were of 2 months' duration and had the same coloration as the adjacent normal mucosa. Histopathologic examination showed orthokeratinized stratified squamous epithelium with acanthosis, some areas of club-shaped rete ridges, and a few superficial epithelial cells with koilocytic changes and a mitosoid-like appearance. A diagnosis of MEH was established. Although MEH tends to occur in the first 2 decades of life, it can be encountered in elderly patients as well.

Salivary Gland Tumors: A 15- year Report from Iran.

OBJECTIVE: The aim of this study was to document the clinicopathologic characteristic of salivary gland tumors in Tehran, Iran, over a 15-year period. MATERIAL AND METHOD: A retrospective study was conducted on salivary gland tumors diagnosed at two pathology centers of Shahid Beheshti University of Medical Sciences from March 2000 to March 2015. Patient age, sex, tumor site and frequency, as well as clinical and radiographic features and histopathologic diagnosis constituted the main analysis outcome measures. RESULTS: Of the 45429 biopsies conducted over 15 years, 6065 (13.3%) cases were oral and maxillofacial lesions and 937 (15.4%) of these had tumoral diagnoses. Of the 937 tumoral cases, 184 (19.6%) were salivary gland tumors and among 184 cases, 65 (35.3%) were benign and 119 (64.7%) were malignant. Pleomorphic adenoma was the most frequently occurring tumor, comprising 32.6% of all tumors, followed by mucoepidermoid carcinoma (27.1%) and adenoid cystic carcinoma (22.2%). Tumors were frequently reported in minor salivary glands (75%), particularly in the palate with 89 (48.4%) cases. The peak ages of incidence were the fourth and sixth decades of life. Malignant salivary gland tumors showed a predilection for females (72.9%), which was statistically significant (P < 0.01). CONCLUSION: The data presented herein are similar to previously published reports in other countries and other areas of Iran. However, some differences were observed in our study, such as higher overall frequency, a lower mean age of patients with malignant tumors, and the particular sites of involvement. These differences can be attributed to racial factors, the pathology centers of sample collection, and the duration of the studies.

Prognostic implication of CD57, CD16, and TGF-ß expression in oral squamous cell carcinoma.

BACKGROUND: Natural killer (NK) cells are important immune effector cells against tumors especially in the absence or reducing MHC class I antigen. Downregulation of CD16 receptor is accompanied by decreasing NK cell-killing activity. It has also been shown that some of tumor cells can evade from immune system through producing transforming growth factor beta (TGF-ß) and affect prognosis. The objective of this study was to evaluate the prognostic significance of CD57(+) and CD16(+) cells and TGF-ß expression in samples of oral squamous cell carcinoma (OSCC). METHODS: CD57, CD16, and TGF-ß expressions were examined immunohistochemically in 57 cases of OSCC. The relationship between markers' expression and clinicopathologic data using bivariate and multivariate analysis was assessed. RESULTS: Multivariate analysis revealed that CD57 expression [HR 17.34 (95% CI 3.815-78.830); P < 0.001] and mode of invasion [HR 0.362 (95% CI 0.138-0.947); P = 0.038] correlated with survival rate, but no relation between CD57 expression and mode of invasion was seen (P = 0.96). Furthermore, no correlation between CD57, CD16, and TGF-ß expression was found. CONCLUSION: These findings suggest that CD57 expression and mode of invasion are independent prognostic factors of survival in OSCC patients.

Giant Osteoma of Mandible Causing Dyspnea: A Rare Case Presentation and Review of the Literature.

Osteomas are benign slow growing tumors of bone. Tumors are usually asymptomatic until they attain remarkable size and cause asymmetry or dysfunction. In view of few reported cases of giant osteoma of mandible, this article presents a case of giant osteoma of left mandible in a 53-year old male causing dyspnea due to compression of air way space.

Prognostic factors of survival rate in oral squamous cell carcinoma: clinical, histologic, genetic and molecular concepts.

Oral squamous cell carcinoma (OSCC) represents 95% of all forms of head and neck cancers. The five-year survival rate of OSCC patients has been reported approximately 50%, which is not satisfactory despite new treatment modalities. The aim of the current review is to present factors (histologic, clinical, genetic and molecular biomarkers) correlated with survival rate in OSCC patients. A web-based search for all types of articles published was initiated using MEDLINE/PubMed. The search was restricted to articles focusing on relevant clinical, histologic, genetic and molecular factors of survival rate in OSCC and presenting new concepts in this field. Mode of invasion, presence of lymph node metastasis, extra-capsular spread, surgical margins and invasive tumor front grade are clinical and histologic parameters, which are strongly associated with survival rate. Focusing on selected proteins, wide range of molecular markers and gene alterations involving in cell cycle regulation, apoptosis, cell migration, cell adhesion and tumor microenvironment have been documented. Among well-known molecular markers, cyclin dependent kinase, survivin, CD44, BUBR1, and heat shock proteins (27,70) can be considered as independent prognostic factors of survival rate. The identified prognostic factors imply a relatively comprehensive understanding of factors related to survival rate in OSCC patients, and provide an additional tool for selecting patients who need more aggressive treatment design.

A 10-year retrospective study on odontogenic tumors in Iran.

OBJECTIVE: The aim of this study was to review cases of odontogenic tumors diagnosed in two pathology centers in Tehran, Iran, during a 10-year period. STUDY DESIGN: Patients' records were seen at two teaching pathology Centre's of Shahid Beheshti University between the months of March 2000 to 2010 with histologic diagnosis of any type of odontogenic tumors. The records were analyzed for frequency, age, sex, site, as well as clinical, radiographic and histopathologic findings. RESULTS: Of 30706 biopsies, 4767 (15.5%) cases were diagnosed as oral and maxillofacial lesions. Among these, 720 cases were tumoral with 188 (26.1%) cases of odontogenic tumors. Tumors with odontogenic epithelium origin formed 70.2% of total numbers of odontogenic tumors. Mixed odontogenic tumors and tumors of odontogenic ectomesenchyme comprised 12.2% and 17.5% of the cases respectively. Ameloblastoma, with a frequency of 62.2% was the most common tumor in this review which was followed by odontoma and odontogenic myxoma. CONCLUSION: Although there are few studies on odontogenic tumors in literature, the comparison of our results with existing data shows significant differences in the distribution of tumors and age of patients, which may be due to ethnic features and geographic distribution of patients. Future studies on other ethnic groups are essential for further clarification of the findings in this research.

Correlation of P53 and granzyme B expression in oral squamous cell carcinoma with clinicopathologic findings.

BACKGROUND: The present study aimed to evaluate the correlation of P53 and granzyme B (GB) expression, and also the relationship between P53 expression and GB+ cell density with lymph node metastasis, histologic grade, and inflammation intensity in oral squamous cell carcinoma (OSCC).  METHODS: Immunohistochemical technique with P53 and GB antibodies were performed on stored paraffin blocks from 48 patients with OSCC (with lymph node metastasis n = 24; without lymph node metastasis n = 24). The density of GB expression was quantified both in invasive front (peritumoral ) and within cancer nests (intratumoral ). RESULTS: P53 positivity was seen in 13 (54.16%) cases of the nonmetastatic group and 14 cases (58.3%) in the metastatic group. A significant correlation was seen between P53 immunoexpression and histologic grade (P = 0.047), but there was no significant correlation between P53 expression with lymph node metastasis and inflammation intensity. The density of GB+ cells in the peritumoral zone correlates with a higher intratumoral GB expression (P = 0.001) and was significantly higher in the nonmetastatic group (P = 0.029). No significant correlation between GB and P53 immunoexpression, lymph node metastasis, or inflammation intensity was seen. CONCLUSION: The present study showed that the presence of a higher density of GB+ cells infiltrating the peritumoral area may have an important role against tumoral cells, prevent lymph node metastasis, and better prognosis in OSCC patients.

Cyclin d1 expression in odontogenic cysts.

OBJECTIVE: In the present study expression of cyclin D1 in the epithelial lining of odontogenic keratocyst, radicular cyst, dentigerous cyst and glandular odontogenic cyst was investigated to compare proliferative activity in these lesions. MATERIAL AND METHOD: Immunohistochemical staining of cyclin D1 on formalin-fixed, paraffin-embedded tissue sections of odontogenic keratocysts (n=23), dentigerous cysts (n=20), radicular cysts (n=20) and glandular odontogenic cysts (n=5) was performed by standard EnVision method. Then, slides were studied to evaluate the following parameters in epithelial lining of cysts: expression, expression pattern, staining intensity and localization of expression. RESULTS: The data analysis showed statistically significant difference in cyclin D1 expression in studied groups (p < 0.001). Assessment of staining intensity and staining pattern showed more strong intensity and focally pattern in odontogenic keratocysts, but difference was not statistically significant among groups respectively (p=0.204, 0.469). Considering expression localization, cyclin D1 positive cells in odontogenic keratocysts and dentigerous cysts were frequently confined in parabasal layer, different from radicular cysts and glandular odontogenic cysts. The difference was statistically significant (p < 0.01). CONCLUSION: Findings showed higher expression of cyclin D1 in parabasal layer of odontogenic keratocyst and the entire cystic epithelium of glandular odontogenic cysts comparing to dentigerous cysts and radicular cysts, implying the possible role of G1-S cell cycle phase disturbances in the aggressiveness of odontogenic keratocyst and glandular odontogenic cyst.

Evaluation of PKM2 and MAPK8IP2 Polymorphism in Ameloblastic Carcinoma: A Retrospective Quantitative Study.

Ameloblastic carcinoma (AC) is a rare malignant epithelial odontogenic tumor that histologically retains the features of ameloblastic differentiation and exhibits cytological features of malignancy in the primary or recurrent tumor. It may develop within a preexisting ameloblastoma or arise de novo or from an odontogenic cyst. Epidemiological evidence shows that human cancer is generally caused by genotoxic factors, genes involved in the susceptibility of cancer, including those involved in metabolism or detoxification of genotoxic environment and those controlling DNA replication. Nowadays, gene polymorphism has an important role in development of malignant tumor. We report a case series study of ameloblastic carcinoma and ameloblastoma to show the role of PKM2 and MAPK8IP2 polymorphisms in these tumors. The DNA was extracted separately from specimens in paraffin sections of the tumor. Polymorphism of these genes was determined by PCR-RFLP (Polymerase Chain Reaction-Restriction fragment length polymorphism) method. The allele distributions of all samples were in Hardy-Weinberg equilibrium. The genotype and allele distribution in these genes were not statistically different between patients and controls.

A 10-year retrospective study on malignant jaw tumors in Iran.

OBJECTIVE: The aim of this study was to review cases of malignant tumors of jaw bones diagnosed in 2 pathology centers in Tehran, Iran, during a 10-year period. MATERIALS AND METHODS: Patients' records were seen at 2 teaching pathology centers of Shahid Beheshti University between March 1999 and March 2009 with histologic diagnosis of any type of malignant jaw tumors. The records were analyzed for frequency, age, sex, site, as well as clinical, radiographic, and histopathologic findings. RESULTS: Of 30,706 biopsies, 4767 (15.5%) were diagnosed as oral and maxillofacial lesions. Among these, 720 cases were tumoral and 67 cases were malignant jaw tumors. Osteosarcoma (41.79%) was the most common tumor in this review, which was followed by mucoepidermoid carcinoma and ameloblastic carcinoma, respectively. Patients' ages ranged from 9 to 71 years, with a mean of 38 years and male predominance. CONCLUSIONS: There are limited studies on malignant jaw tumors in literature, but comparing our result with the available data, there were differences regarding frequency and age distribution. This may be related to racial and geographic characteristics. More studies on other population are needed.