Background: Squamous cell carcinoma (SCC) is the most prevalent malignant neoplasm of the oral cavity that exhibits certain histological variations. Verrucous carcinoma (VC) is an uncommon exophytic low-grade well-differentiated variant of SCC. Cellular differentiation and morphology play important roles in cell functions and maintenance of structural integrity .As the cancer is a malignant process in which disorder of the cell growth and behavior occurs, such changes may differ in different tumor types and within different grades of the same tumor. Materials and Methods:Forty two formalin – fixed, paraffin – embedded tissue blocks were included in this study (30 blocks were diagnosed as OSCC and 12 blocks were diagnosed as OVC). An immunohistochemical staining was performed using anti moesin, anti CK14 and anti MMP7 monoclonal antibodies. Results: Moesinimmunoreactivity was recognized in all the studied groups with predominant cytoplasmic expression in OSCC & membranous expression in OVC. No difference was noticed between 2 studied groups &between different grades of OSCC. Cytokeratin 14 positivity was noticed in all studied groups with significant difference between OSCC&OVC (p=0.012) & there was a significant difference between the different grade of OSCC (p=0.047). MMP7 expression was observed in the all studied groups with predominant cytoplasmic pattern in OSCC & nuclear pattern in OVC. No difference was found between the 2studied groups &between the different grades of SCC. A Strong positive linear correlation between MMP7&CK14 was noticed. Conclusion: Verrucous carcinoma has a specific pattern for moesin and MMP7 that differs from OSCC, however; the difference is not significant. CK14 immunoreactivity indicated a significant difference in the degree of cellular differentiation between OSCC &OVC.
