Methylene Blue as a Diagnostic Aid in the Early Detection of Potentially Malignant and Malignant Lesions of Oral Mucosa

Abstract

BACKGROUND: In vivo stains are the prompt resources, which have emerged in recent years to aid asclinical diagnostic tools in detecting early potentially malignant and malignant lesions. Toluidine blue,by its property of retaining in the increased DNA and RNA cellular activity areas, aids in delineating thesuspicious areas. However, it is hazardous if swallowed, and has been shown to have toxicity tofibroblasts. Methylene blue has a similar chemical structure and exhibits similar physicochemicalproperties as toluidine blue. It is less toxic to the human body and has recently been proposed forscreening some gastrointestinal or prostate tumors. The application of this material in detecting orallesions has so far not been addressed. The objective of this study was to evaluate the sensitivity andreliability of in vivo staining with methylene blue as a diagnostic adjunct in screening for oral malignantor potentially malignant lesions.METHODS: The present study involved the examination of 75 patients suspected of having oralmalignant or potentially malignant lesions by methylene blue staining. The results of methylene blueuptake were compared with a simultaneous biopsy of these lesions.RESULTS: The overall sensitivity was 95% (100% for malignancy and 92% for potentially malignantlesions) and specificity was 70%. The positive predictive value was 91% and negative predictive value of80% was observed in the study.CONCLUSION: We consider that methylene blue staining is a useful diagnostic adjunct in a large,community-based oral cancer screening program for high-risk individuals.