Immunohistochemical localization of intermediate filament proteins in calcifying epithelial odontogenic tumors

Three calcifying epithelial odontogenic tumors (CEOT) were examined immunohistochemically. The localization of intermediate filaments was characterized through the use of polyclonal anti-keratin antiserum (TK which detects 41-65 kd keratins), 2 monoclonal keratin antibodies (PKK1 specific for the 44, 46, 52 & 53 kd keratins and KL1, specific for the 55-57 kd keratins) and monoclonal antibodies for vimentin and desmin. The tumor epithelial cells were slightly positive or negative for PKK1 detectable keratins, but slightly to strongly positive for KL1 and TK antibodies. Tumor epithelium was slightly positive for vimentin but negative for desmin. The tumor foci were composed of both dark-staining and pale-staining cells; the former had a more intense reaction with KL1 and TK antibodies than the latter. Homogeneous acellular material was either PAS-positive or negative, with or without calcification, and keratin-negative.