Objective: To clarify epithelial cell ultramicrostructure changes in oral carcinogenesis.
Methods: The epithelial cell ultramicrostructures in tongue carcinogenesis induced by 4-nitroquinoline-1-oxide (4NQO) were observed by transmission electron microscope.
Results: With the progress of oral carcinogenesis, regular changes of epithelial cell were showed: decrease in tonofibril, keratohyaline granules, desmosome; and increase in mitochondria. The basement membrane was broken in some severe dysplasia (sDP) and was broken through by parts of cell processes in in situ carcinoma (ISC).
Conclusion: Oral carcinogenesis is a multistep process. Epithelial cell aberrant differentiation is showed by a decrease in the synthetic products of epithelium cell.