Immunohistochemical localization of keratin, vimentin and myosin in salivary gland tumors

An immunohistochemical study on keratin, vimentin, and myosin was performed in 117 specimens of human salivary gland under normal and several neoplastic conditions. In normal glands, positive immunostaining for keratin was observed in the inner cells of all ductal systems, whereas myosin and vimentin were the cytoskeletal components of myoepithelial cells. In pleomorphic adenoma, the inner cells showing a tubular pattern demonstrated positive immunostaining for keratin, and the outer cells as well as the neoplastic cells with a solid and myxoid pattern exhibited positive immunostaining for all antibodies. Monomorphic tubular and trabecular adenoma, and adenolymphoma showed positive immunostaining for keratin, although one case of tubular adenoma exhibited positive immunostaining for all antibodies. Squamous cell carcinoma, adenosquamous carcinoma, and mucoepidermoid tumor showed positive immunostaining only for keratin, but one case of adenocarcinoma, two cases of adenoid cystic carcinoma, and clear cell tumor disclosed positive immunostaining for keratin and vimentin.