Buccal Micronuclei Assay as a Tool For Biomonitoring DNA Damage in Oral Lichen Planus.

INTRODUCTION: The malignant transformation rate of Oral Lichen Planus (OLP) is between 0% and 5.8%. Oral lesions of lichen planus clinically presents itself multifocally, simulating the process of field cancerization in high risk malignancies. The Buccal MicroNucleus Cytome Assay (BMN Assay) provides a platform to identify the high risk individuals by evaluating the markers of nuclear damage at an earliest micro invasive phase. AIM: To evaluate DNA damage in exfoliated buccal mucosal cells in individuals with oral lichen planus lesions and thereby to delineate the high risk group. MATERIALS AND METHODS: Buccal smears from 22 OLP and 10 control samples were stained in modified Feulgen-Rossenback reaction for micronuclei assay. Cytological evaluation of number of MicroNucleated cells (CMN), Total Number of Micronuclei (TMN) in micronucleated cells was done in both groups. RESULTS: Frequency of micronucleated cells (CMN) when compared among the study and control group, a mean value of 4.27 ± 1.80 and 0.90 ± 0.88 were obtained respectively. On comparing the total number of micronuclei in the micronucleated cells (TMN) between the study and control groups, a mean value of 5.38 ± 2.42 and 1.5 ± 0.88 were obtained respectively. CONCLUSION: There was a significant increase in the frequency of micronuclei and the micronucleated cells in the oral lichen planus as compared to normal individuals.

Myoepithelial Cells (MEC) of the Salivary Glands in Health and Tumours.

Myoepithelial cells (MEC) are found in the secretory units of many mammalian exocrine glands such as mammary, sweat, lacrimal and salivary glands. They are interposed between the secretory cells and the basal lamina. Immunohistochemically they are found to contain keratin intermediate filaments and are, therefore, considered to have an epithelial origin but at the same time they contain a large number of myofilaments which represent a massive expression of contractile proteins such as actin, myosin, calponin and caldesmon. Thus have smooth muscle like property also and hence the name. Numerous functions of MEC have been described, the most important of them being important for contraction of the glands and recently it has been found to prevent tumour progression. It should be noted that the diversity in the occurrence and dilemma regarding the pathogenesis of salivary gland tumours is due to lack in uniformity regarding the cells participating in its oncogenesis, especially the MEC. Also proper and extensive studies regarding MEC are very limited and thus have posed difficulty for a pathologist to understand this cell. In this review we try to bring about a thorough description of this cell in both physiological and pathological aspects.

Evaluation of myofibroblasts in oral squamous cell carcinoma using H1 calponin: An immunohistochemical study.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral mucosa. Stromal myofibroblasts play an important role in tumor invasion and metastasis, due to its ability to modify the extracellular matrix. The purpose of this study was to evaluate and compare the presence of myofibroblasts in normal mucosa, early invasive carcinoma and different grades of OSCC. MATERIALS AND METHODS: The study included the archival tissues of 18 OSCC of well, moderate and poorly differentiated grades, three early invasive carcinomas and five normal mucosa. Myofibroblasts were identified by immunohistochemical detection of h1 calponin. RESULTS: The percentage and intensity of h1 calponin were examined and positive immunostaining was observed in the myofibroblasts of all SCCs and early invasive carcinomas; however, these cells did not stain in the normal epithelium specimens. The presence of myofibroblasts was significantly higher in invasive pattern of OSCCs compared to normal mucosa cases (P < 0.070). A significant difference was not observed between the different grades of OSCC (P ≤ 0.812). CONCLUSION: These findings show the presence of myofibroblasts in OSCC but not in normal mucosa, suggesting that the genetically altered epithelium (carcinomatous epithelium) may have an inductive effect on the adjacent stroma to produce myofibroblasts. Also transdifferentiation of myofibroblasts is induced somewhere in the invasive stage of SCC irrespective of the epithelial cell differentiation.

Unusual presentation of nasopharyngeal (juvenile) angiofibroma in a 45 year old female.

Juvenile nasopharyngeal angiofibroma is a rare tumour, comprising 0.05% of the head and neck tumours, histologically benign, locally invasive, and has a specific predilection for nasopharynx and adolescent males. This article presents an unusual case of nasopharyngeal angiofibroma in a 45-year-old female patient, manifesting as a destructive maxillary lesion and discusses the two most important factors regarding this tumour, the etio-pathogenesis and spread.

Expression of inducible nitric oxide synthase in the epithelial linings of odontogenic keratocyst, dentigerous cyst and radicular cyst: a pathological insight.

BACKGROUND: The present study is aimed at analyzing the expression of inducible nitric oxide synthase (iNOS) in the epithelial lining of odontogenic keratocyst (OKC), dentigerous cyst (DC), radicular cyst (RC) in order to understand the possible role of iNOS with special reference to its neoplastic nature and local aggressive of cysts. AIM: The primary aim of the following study is to analyze the immunohistochemical expression of iNOS and secondary aim is to compare the iNOS expression, pattern and intensity of staining among the epithelial linings of OKC, DC and RC. MATERIALS AND METHODS: iNOS in the epithelial lining cells were analyzing in 10 OKC's, 10 DC's and 10 RC's using immunohistochemistry. The percentage of positive cells was assessed and presented as mean ± standard deviation. The correlation with respect to the intensity and percentage of staining within the epithelial linings of OKCs, DCs and RCs was carried out using (analysis of variance and Student's t-test) Chi-square test. RESULTS: Staining intensity of iNOS portion was seen in the entire thickness of the epithelial linings of OKC, whereas in DC's only one case had entire thickness of the epithelial lining staining and in RC's none of the cases showed entire thickness of staining. On comparing the staining intensity of iNOS between OKC, DC and RC groups, using Chi-square test, there was a statistically significant difference between these groups (P < 0.01). On analyzing the immuno-reactivity of iNOS in OKC, DC and RC there was a positive variable expression iNOS between the cysts. CONCLUSION: iNOS was over expressed in OKCs when compared with DC and RC suggesting that iNOS may contribute to the aggressive behavior of OKC. This is yet another evidence to support that OKC is the neoplasm.

Central odontogenic fibroma of the maxilla.

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.