Toluidine blue application to detect dysplasia and malignant changes in patients with oral lichenoid lesions

Abstract

Background Oral lichen planus (OLP) is a chronic disease with immune-mediated pathogenesis which can be premalignant. Oral lichenoid dysplasia (OLD) is a precancerous process with lichenoid features which is frequently confused with OLP. Objective In this study, we aimed to investigate the efficacy of toluidine blue (TB) administration before biopsy to detect the dysplastic changes in patients who were clinically diagnosed with OLP. Methods Thirty consecutive patients with oral lichenoid lesions whose clinical findings were consistent with OLP were included in the study. Demographic and clinical characteristics of the patients studied were recorded and clinical photos were taken before and after the administration of TB. Areas to be biopsied were determined according to the results of the TB staining. Histopathologically, all the specimens were evaluated in terms of the diagnostic features of OLP and the presence of dysplastic findings. ResultsThe mean age of the 30 patients (21 females, 9 males) included in the study was 51.03 (26-70 years) and the median value of disease duration was 12.00 ± 67.23 months (2-360 months). Six patients (20.0%) had positive staining after application of TB. Histopathological examination revealed OLP findings in 17 patients (56.7%), OLP and dysplasia findings in nine patients (30.0%) and lichenoid dysplasia in four patients (13.3%). Dysplasia was detected in all of the lesions (six patients) which were stained blue with TB. The relationship between staining and dysplasia was significant (p<0.05). OLP and dysplasia were observed in four of these six patients (66.7%), and lichenoid dysplasia was observed in the other two (33.3%). The relationship between presence of dysplasia and presence of mitosis was found statistically significant in patients with histopathological dysplasia (p<0.05). When the presence of mitosis was evaluated in biopsies taken from the stained lesions, a statistically significant relation was found (p<0.05). Conclusions In our study, it was observed that dysplasia was detected in all stained areas after the application of TB to clinically classical OLP patients, but there was no staining in some patients despite the presence of dysplasia. Therefore, the sensitivity of the application was 46%, specificity was 100%, positive predictive value was 100% and negative predictive value was 70.8%. TB application is a specific test to detect the dysplasia; however because of the low sensitivity in oral lichenoid lesions, another method is needed to increase the sensitivity.