Expression of E-cadherin and alpha-catenin in epithelial odontogenic tumors: an immunohistochemical study.

To clarify the possible role of cell adhesion in epithelial odontogenic tumors, expression of E-cadherin and alpha-catenin was examined by an immunohistochemical method. These molecules showed pericellular distribution in epithelial cells of the tooth germ and its derived tumors. In ameloblastomas, E-cadherin and alpha-catenin were expressed strongly in central polyhedral cells and slightly in peripheral columnar cells. These features resembled those of epithelial components in the tooth germ tissues, retaining cytodifferentiation of odontogenic epithelium. Expression of the molecules in the variants of ameloblastomas showed loss in the keratinizing areas and reduction in the granular cell clusters, suggesting terminal differentiation of the tumor cells. Calcifying epithelial odontogenic tumors and a clear cell odontogenic tumor preserved E-cadherin and alpha-catenin expression without a specific feature for histogenesis or cytodifferentiation. One case of two malignant ameloblastomas showed prominent reduction in expression of E-cadherin and alpha-catenin.