Proliferative activity of myoepithelial cells in of mucoepidermoid carcinoma

AIM: The aim of the study is to investigate the role of myoepithelial cells in the pathogenesis of mucoepidermoid carcinoma (MEC) using the double immunohistochemical staining; α smooth muscle actin (α-SMA)as specific marker for the myoepithelial cell differentiation and proliferative cell nuclear antigen (PCNA) as a marker for proliferative activity of myoepithelial cells. MATERIAL AND METHODS: Retrospective study of twenty salivary gland specimens (ten MEC and ten normal salivary glands) were studied using double immunohistochemical labeling for α smooth muscle actin α-SMA) and proliferative cell nuclear antigen (PCNA). The SPSS statistical package was used for data analysis (IBM SPSS Statistics for Windows, Version 20.0, Released 2011, IBM Corp, and Armonk, NY, USA). RESULTS: In mucoepidermoid carcinomas, no positivity of α-SMA was seen in neoplastic cells (Frequent test), and it was just observed in the stroma of tumor, in the walls of blood vessels whereas, PCNA was positive, especially in high-grade tumors. In contrast, in normal salivary glands, the proliferating myoepithelial cells are stained by both α-SMA and PCNA. CONCLUSIONS: We believe that the myoepithelial cells have no a role in the development of mucoepidermoid carcinoma.