Investigation of DNA-content of leukoplakia cells or oral mucosa.

DNA-histograms of smears of 11 plain leukoplakias, one of a precancerous leukoplakia, three of leukoplakia carcinoma in early stage, and one of a keratotic seqamous cell carcinoma of the floor of the mouth were prepared. The cell nuclei of the plain leukoplakia are mostly diploid, a small proportion has a DNA-content of 4 C. Intermediate values or polyploid nuclei are absent. In precancerous leukoplakia, intermediate values were noticed; in the cases of carcinoma in early stage, intermediate and polyploid nuclei were present, and in one case only polyploid nuclei. Only 2C and 4C nuclei occurred in a case of keratotic squamous cell carcinoma, which in comparison to earlier examined cases must be termed DNA negative.