Immunohistochemical expression of minichromosome maintenance-3 protein in pleomorphic adenoma and mucoepidermoid carcinoma

Introduction Salivary gland tumors represent a diverse set of tumors. Pleomorphic adenoma (PA) and mucoepidermoid carcinoma (MEC) are the most common benign and malignant salivary gland tumors respectively. Proliferation markers have been used to determine the behavior and prognosis of benign and malignant tumors. Minichromosome maintenance (MCM) proteins are family of six major members (MCM-2–7), which have similar biochemical functions and are essential for the process of DNA replication. MCM-3 is a member of this family, which present during proliferation of normal cells and neoplastic cells while absent in quiescent ones. Aim To assess the expression of MCM-3 in PA and MEC, and to correlate the expression of MCM-3 with the collected clinical data of PA and MEC. Materials and methods This retrospective study was performed using 40 paraffin-embedded tissue blocks of PA and MEC (20 cases each). Clinical data were collected. The specimens were stained by conventional hematoxylin and eosin staining to confirm the diagnosis and then immunohistochemical staining was performed by using antibody against MCM-3 to evaluate the expression. Results MCM-3 expression was significantly correlated to grades of MEC and significantly different between MEC and PA. Furthermore, MCM-3 expression was positively correlated to female cases of MEC. Conclusion MCM-3 may be used as a sensitive proliferative marker for PA and MEC.