Micronuclei Comparison in Lichen Planus and Oral Lichenoid Responses

Lichen planus is a mucocutaneous chronic inflammatory disease with unknown etiology. Malignant potential of oral lichen planus (OLP) and lichenoid reactions (OLR) are controversial. Since micronucleus frequency of cells is representative of risk of malignancy, the aim of present study was to evaluate micronucleus frequency in these lesions. In this cross-sectional study, study group consisted of 20 OLP and 20 OLR which clinically and histopathologically had been confirmed and 20 healthy individuals without oral lesions and systemic disease who presented in oral medicine department of Babol dental college. After receiving written consent, smears were prepared from lesion site at buccal mucosa by cytobrush and were stained at laboratory using Papanicolaou stain. In each slide 500 cells were assessed under light microscope at 400X magnification; mean number of micronucleated cells and mean total numbers of micronuclei were calculated. Mean number of micronucleated cells in OLP, OLR and normal mucosa were 5.20±3.73, 5.65±3.66 and 0.95±1.19 and number of micronuclei were 6.75±4.94, 8±4.66 and 1.30±1.72 respectively. Mean number of micronucleated cells and number of micronuclei were significantly greater in OLP and OLR than normal mucosa (p<0.001) but there were no significant differences between OLP and OLR (p=0.67 and p=0.36 respectively). There were no significant differences in mean number of micronucleated cells between reticular and erosive subtypes of OLP and also OLR (p=0.96). There were also no significant differences in mean number of micronuclei between these subtypes (p=0.96 and p=0.93 respectively). The results of this study indicated that significant increase in micronucleus frequency of OLP and OLR are probably indicative of higher risk of malignancy in these lesions.