Role of p63 immunohistochemistry in diagnosing Salivary gland neoplasms

Introduction: Salivary gland tumors are uncommon neoplasms encountered in the head and neck region. Salivary gland neoplasms have varied histopathological findings with dual cell differentiation with some of the tumors showing morphologic overlap. Detailed histomorphologic analysis along with judicious application of immunohistochemistry are required to identify dual cell differentiation and to make a proper diagnosis. p63 is a selective immunohistochemical marker of basal stem cells of stratified epithelium and of myoepithelial cells which aid in the diagnosis of salivary gland tumors. Objective: To study the role of p63 in the diagnosis of salivary gland tumours. Materials and Methods: The present study was conducted in the Pathology department of M.S Ramaiah Hospital on the surgically resected salivary gland tumor specimens received for routine histopathological evaluation, from January 2010 to December 2014. A total of 66 cases of salivary gland neoplasms were included in the study. Results: Most tumors studied had myoepithelial cells with mixed cytomorphology and had mixed architectural pattern. 66 salivary gland tumors were immunostained for p63 antibody using standard procedures. Pleomorphic adenoma, Adenoid Cystic Carcinoma and Warthin tumor were positive for p63 immunostain with variable intensities. Mucoepidermoid Carcinoma showed positivity in clear, intermediate and squamous cells. Acinic Cell Carcinoma was negative for p63. Conclusion: Proper diagnosis of salivary gland tumor is very important in the treatment and management of the patient. p63 is an important immunohistochemical marker which aid in the diagnosis of salivary gland tumors. The differential localization of p63 in these neoplasms has shed light on the myoepithelial cellular localizations in the salivary gland tumors. Keywords: Histopathology, Salivary gland tumors, dual cell differentiation, immunohistochemistry.