The expression of intermediate filaments and mam-6 antigen in relation to the degree of morphologic differentiation of carcinoma of the head and neck: diagnostic implications.

In this study, the immunoreactivity of several cytokeratin antibodies; 115 D8, a monoclonal antibody against MAM-6, an epithelial membrane antigen; and two vimentin antibodies, is examined in relation to the degree of morphologic differentiation in carcinomas of the head and neck. The results indicate that a relationship exists between the degree of morphologic differentiation and the expression of cytokeratin, MAM-6, and vimentin, as detected by polyclonal antikeratin, 115 D8 and anti-vimentin. Expression of cytokeratin and MAM-6 is reversely related to vimentin. Polyclonal anti-keratin; CAM 5.2, a monoclonal antibody against cytokeratin 8, 18 and 19; and 115 D8, used in combination, were still able to identify the epithelial nature of undifferentiated/spindle cells. Since these immunohistochemical markers precede light microscopic detectable signs of epithelial differentiation, they can be used for the identification of the epithelial nature of undifferentiated/spindle tumors of the head and neck.