DNA ploidy in oral lichen planus, determined by image cytometry

Background: The objective of this study was to use image cytometry to determine the degree and frequency of DNA ploidy in biopsies of reticular and atrophic-erosive oral lichen planus and to analyze 14 karyometric measurements of the nuclei of epithelial cells from each specimen. Methods: A total of 40 slides were analyzed, each of them representing one biopsy of one oral lichen planus (OLP) lesion from each one of the 40 patients (cases) studied. Specimens were embedded in paraffin and comprised 20 slides of reticular oral lichen planus (group R) and 20 slides of atrophic-erosive oral lichen planus (group AE). Results: Group R, the reticular lichen samples, had 18 diploid cases and two aneuploid cases. Group AE, the atrophic-erosive lichen samples, had 10 diploid cases, one tetraploid case, and nine aneuploid cases. Of the 14 karyometric measurements of the nuclei of OLP epithelial cells analyzed, the group R mean values for mean density and minimum density were significantly greater than the group AE mean values, and mean roundness in group AE was significantly greater than in group R (t-test: P < 0.05). Conclusions: The most common degree of DNA ploidy in OLP lesions was diploidy. Comparing the two groups (chi-square test of association P = 0.021) demonstrated that diploidy was associated with the reticular clinical form of OLP, while aneuploidy was associated with the atrophic-erosive clinical form of oral lichen planus.