Microspectrophotometric determination of DNA in oral lesions.

The DNA content of the epithelial basal cells of oral lesions was determined by Feulgen microspectrophotometry. The DNA histograms of the radicular cysts showed a definite peak in the diploid range and a slight deviation to the right. The keratocysts also showed a well-defined modal peak in the diploid range; however, another cell population defined a peak in the tetraploid range. In leukoplakias of the oral cavity, two different profiles of DNA distribution were found. Where both the clinical and microscopic traits defined a nondysplastic lesion, the histogram showed a diploid peak and a percentage of cells in diploid-tetraploid range. For the more active lesion, a shift of the mode towards higher values was evident. The microspectrophotometric studies of oral epidermoid carcinomas showed a broad distribution towards the right and ill-defined modal values.