The use of toluidine blue in the detection of pre-malignant and malignant oral lesions

Abstract

The purpose of this study was to evaluate the efficacy of the toluidine blue (TB) test as a diagnostic tool in the detection of malignant and dysplastic lesions of the oral cavity. This study was carried out because of a lack of consensus among different authors on the utility of TB, as well as to determine useful adjuncts to detect oral pre-cancer and cancer. The study included 160 patients with oral mucosal disorders that included suspicious or malignant lesions detected at clinical visual examination, confirmed by histopathological evaluation. All lesions were submitted to TB staining. The sensitivity and specificity for the detection of malignant or dysplastic lesions by this test were 65.5% and 73.3%, respectively. Overall, the detection rate with TB (sensitivity) was slightly lower compared with those reported by other authors but the specificity was comparable to several reports. Positive predictive value (35.2%) was also lower than previous studies, whereas negative predictive value (90.6%) was similar. The simplicity of the test procedure and the validity of derived values suggest TB staining can be a valuable adjunct to the diagnostic process, as long as it is carefully correlated with the clinical characteristics of the mucosal disorder and histopathological diagnosis.