Expression of cell adhesion molecule CD44 in mucoepidermoid carcinoma and its association with the tumor behavior

BACKGROUND The most common malignant salivary gland tumors that affect both adult and children is mucoepidermoid carcinoma. It usually affects both minor and major salivary glands but parotid gland is considering the most common site in which this tumor arises. CD44, a trans-membrane glycoprotein, is an adhesion molecule of cell surface that play a role in the connections between cell-cell and cell-matrix. Many malignant tumors express high levels of CD44, thus, CD44 may be used as an indicator of aggressive behavior of some human malignancy. We evaluate CD44 expression in different grades of mucoepidermoid carcinoma and determine whether expression of CD44 can be used to predict tumor aggressiveness. METHODS Fifteen cases of mucoepidermoid carcinoma were retrieved from the oral pathology archives and grouped according to the histological grade as well as the clinical behavior regarding metastases and/or recurrence. Tissue sections were immunohistochemically stained for CD44. CD44 staining was scored for intensity and proportion of cells stained. RESULTS A higher proportion of high-grade tumor tissues showed moderate or strong CD44 staining compared to low-grade tumors. Additionally, CD44 expression was stronger in tumors from patients with recurrences or metastases, but theses differences were not statistically significant. CONCLUSION Our result showed that mucoepidermoid carcinomas are immunohistochemistry positive to CD44 compare to normal. A trend of CD44 expression associated with different histological grading and aggressive behavior of this tumor.