Utility of toluidine blue as a diagnostic adjunct in the detection of potentially malignant disorders of the oral cavity--a clinical and histological assessment.

BACKGROUND:  The value of chairside adjunctive tests in the detection of oral potentially malignant disorders (OPMDs) remains uncertain.

OBJECTIVES:  To determine the effectiveness of toluidine blue in detecting leukoplakia and erythroplakia and its accuracy in identifying cases with oral epithelial dysplasia.

MATERIALS AND METHODS:  Ninety-two patients attending two oral medicine clinics in London, presenting with white and red patches of the oral mucosa, were investigated by the application of toluidine blue. Eighty-two patients were clinically diagnosed as OPMDs and 10 were frictional keratoses. A surgical biopsy was performed to assess epithelial dysplasia.

RESULTS: Of 64 oral leukoplakias, 34 (53.1%) were positive for toluidine blue and among nine erythroplakias seven stained positive. Of 41 oral dysplasia cases, a little more than half of the lesions (n = 23) were stain positive, an estimated sensitivity of 56.1%. TBlue test had a higher sensitivity for detecting higher-grade dysplastic lesions (5/8 moderate dysplasia, sensitivity 62.5%; 5/7 severe dysplasia; sensitivity 71.4%) compared with lower grades of dysplasia, but the differences were not significant (P = 0.60).

CONCLUSIONS: We report here the utility of TBlue for the detection of oral leukoplakia and erythroplakia. The test has the potential to detect OPMDs and yielded a sensitivity of 56.1% and specificity of 56.9% to detect oral epithelial dysplasia.