Toluidine blue staining in the detection of oral precancerous and malignant lesions.

One hundred thirty-two consecutive patients suspected of having malignant or precancerous oral lesions were studied by comparing toluidine blue dye uptake clinically with a simultaneous biopsy. The histopathologic diagnosis confirmed 57 squamous carcinomas, 42 epithelial dysplasias, and 33 benign mucosal changes. Overall accuracy of the toluidine blue uptake was 91%. In the dysplastic and malignant lesions the false negatives were 2%, and there were 30% false positives in the benign lesions. It was concluded that toluidine blue staining is a useful adjunct to careful examination, clinical judgment, and biopsy.