الفهرس 
INTRODUCTION AND REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
CD44 is a cell adhesion molecule that functions in cell proliferation, cell differentiation, cell migration, angiogenesis, lymphocyte homing to peripheral lymphoid tissues, presentation of cytokines, chemokines, and docking of proteases at the cell membrane, as well as in signaling for cell survival. CD44 acts also as the main hyaluronan receptor.
In this study the expression of CD44 in Pleomorphic adenoma and Mucoepidermoid carcinoma was detected and correlated in both and in different grades of MEC.
The material of this study consisted of 40 formalin fixed, paraffin embedded specimens of salivary gland tumors. Twenty cases diagnosed as Pleomorphic adenoma and twenty cases diagnosed as mucoepidermoid carcinoma. Cases diagnosed as Mucoepidermoid carcinomas were further categorized into high grade and low grade according to their histological features.
For detection of CD44s antigen, monoclonal mouse antiCD44s antibody was used. Peroxidase-antiperoxidase technique was performed for the immunohistochemical staining using the ready-to-use universal kit.
For all cases, the area fraction of immunopositivity for at least 4 different microscopic fields was measured. The mean area fraction for each case was then calculated and used for statistical analysis.
The results of this study demonstrated that there was a statistically significant increase in CD44 expression in Mucoepidermoid carcinoma over Pleomorphic adenoma and between high grade Mucoepidermoid carcinoma and Pleomorphic adenoma, the pattern of expression was also different in both tumors. There was an overall increase in CD44 in the expression of CD44 Mucoepidermoid carcinoma. This increase was not just due to the higher number of cells showing immunopositivity but also due to the change of pattern of expression within tumor cells. The expression was membranous in Pleomorphic adenoma and both membranous and cytoplasmic in Mucoepidermoid carcinoma (especially so in high grade MEC).
There was no statistically significant difference between the expression, of CD44 in high and low grades Mucoepidermoid carcinoma or between low grade Mucoepidermoid carcinoma and Pleomorphic adenoma. Yet, the pattern of expression varied in both.
from this study it was deducted that over-expression of CD44 correlates with increased proliferative activity and presumably increased cellular motility