Ameloblastoma is a benign tumor of odontogenic origin, commonly found in the jaw bones. The occurrent rate of this tumor in Thai population is much higher than previously reported in the other races. The objective of this study was investigation of the tumor cells from Thai patients by using immunohistochemical and transmission electron microscopic techniques. In addition, cell culture of the tumor was performed as a study model for the tumor cells. The result showed that, immunohistochemically, ameloblastoma cells synthesized high molecular weight cytokeratin, cytokeratin 19 and vimentin. The result suggested these tumor cells were epithelial cells with distinet intracellular proteins. Microscopically, ameloblastoma comprised of ameloblast-like and stellate-like cells. These two types of cells had ultrastructural characteristics of stratified epithelium. The tumor cells were surrounded by different patterns of basement membrane in different types of ameloblastoma. By using cell culture technique, the clone of epithelial tumor cells was successfully established and maintained for a short time, then the cells were replaced by fibroblasts.
