Autoradiographic studies of oral lichen planus

3H cytidine autoradiographic labeling patterns have been categorized into those characteristic for neoplastic, preneoplastic, and normal cell types. Specific differences in the patterns of transcription (RNA synthesis) revealed that the histology of a particular lesion generally correlated with (1) the percentage of cells labeled with the isotope, (2) the number of grains per cell, and (3) their intracellular distribution. When these three criteria of labeling were applied to lesions of the oral mucosa, very interesting data were collected on cases of lichen planus. The benign histologic appearance of the oral lichen planus epithelium exhibited a preneoplastic-appearing autoradiogram, an observation which is of particular interest in view of the fact that a small number of patients with this disease develop intraoral squamous cell carcinoma.