Flow cytometric analysis of nuclear DNA content in oral leukoplakia: relation to clinicopathologic findings.

DNA ploidy of 50 biopsy specimens of oral leukoplakia was investigated by flow cytometry, and the results were compared with the clinicopathologic appearances. The aneuploidy rate of the leukoplakias was 17/50 (34%), and the mean DNA index (DI) of the aneuploid lesions was 1.22, with a range from 0.70 to 1.84. The incidence of the aneuploidy was significantly (P < 0.01) higher in nonhomogeneous leukoplakias (11/18) than in homogeneous lesions (6/32). The aneuploidy rate of the severely dysplastic leukoplakias (11/17) was significantly higher than those of the mildly dysplastic (4/22; P < 0.01) and the nondysplastic (2/11; P < 0.02) lesions. A significant (P < 0.01) difference in the aneuploidy rate was also observed between tongue (12/23) and gingival (2/18) leukoplakias.