RESUMEN
CONTEXT: Inducible nitric oxide synthase (iNOS) is a cytoplasmic enzyme which plays a crucial role in the pathogenesis of oral carcinomas and sarcomas. AIMS: The objective of this study was to analyze the immunohistochemical expression of iNOS in carcinomas and sarcomas affecting the oral cavity in order to understand the possible role of iNOS in their biologic behavior and to correlate iNOS expression with lymph node metastasis in carcinomas and sarcomas. SETTINGS AND DESIGN: Patients, who attended the oral diagnosis department of Vinayaka Missions Sankarachariyar Dental College, were screened, for the purpose of the study. Besides these, paraffin-embedded tissue blocks were also retrieved from archives of the Oral and Maxillofacial Pathology Department. A total of 40 cases (20 carcinomas and 20 sarcomas) were selected for the study. SUBJECTS AND METHODS: A total of 40 cases (20 carcinomas and 20 sarcomas) were selected for the study. Five apparently normal tissues were obtained from the tumor adjacent normal tissue to be used as a control. These were subjected to immunohistochemical staining using antibody to iNOS and evaluated. STATISTICAL ANALYSIS USED: The results were analyzed using the Chi-square test. RESULTS: Among the 20 carcinomas 19 showed a positive immunoreactivity for iNOS and 1 case was negative. Among the 19 immunopositive iNOS cases of carcinomas, 15 cases showed positive lymph node metastasis. Among the sarcomas, positive immunoreactivity for iNOS was seen in 10 hard tissue sarcomas, while the remaining 10 soft tissue sarcomas were negative for iNOS expression. The results were analyzed using the Chi-square test. CONCLUSIONS: iNOS is a reliable marker for lymph node metastasis in carcinomas irrespective of the histologic grade. The high expression in carcinomas shows that the carcinomas elaborate more angiogenesis for growth compared with the sarcomas with the exception of hard tissue sarcomas.
RESUMEN
The central odontogenic fibroma (COF) is a rare benign odontogenic mesenchymal tumor of jaw bones. The World Health Organization (WHO) recognizes two variants of COF namely: 1) Epithelial-rich type (WHO) and 2) epithelial-poor type (simple type). Rare variants like ossifying COF, COF associated with giant cell lesions, and amyloid have been documented. This article presents a case of an epithelial-rich variant of COF in a 24-year-old female. It presented as a bony swelling of the maxilla and appeared as a mixed lesion in radiographs. Histopathology showed a highly cellular fibrous connective tissue stroma with plump fibroblasts and long strands of odontogenic epithelium exhibiting mild eosinophilic to clear cytoplasm. Numerous cementum-like hematoxyphilic calcifications of various sizes akin to dentin or acellular cementum were observed. We believe that clinical and radiographic features of this case may add valuable knowledge to the already existing literature.
RESUMEN
AIMS: Prolonged production of the free radical, nitric oxide (NO) by the enzyme inducible nitric oxide synthase (iNOS) plays an important role in tumour progression by promoting angiogenesis, invasion and inducing mutation in tumour suppressor gene. The purpose of this study is to evaluate the expression and intensity of iNOS in normal oral mucosa, precancer and oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: An immunohistochemical study was performed using rabbit monoclonal antibody to iNOS on archival formalin fixed, paraffin embedded tissues of 5 normal oral mucosal samples, 10 Leukoplakia, 10 oral submucous fibrosis (OSMF) and 15 OSCC of different grades. RESULTS: A statistical significant difference was found between normal oral mucosa, precancer and OSCC in expression of iNOS (p value 0.0015). However, there was no statistically significant difference between the expressions of iNOS within premalignant groups (p value 0.5647) and histological sub-groups of OSCC (p value-0.5647). There was no statistically significant difference in the intensity of iNOS expression within the precancer group, OSCC sub-groups and between precancer and OSCC (p value-0.623). CONCLUSION: The orderly increase in the expression of iNOS from normal, through precancer, to OSCC suggests the essential role played by iNOS in epithelial transformation and tumour formation.
