Oral Medicine
Reliability of toluidine blue application in the detection of oral epithelial dysplasia and in situ and invasive squamous cell carcinomas*,**

Presented at the 5th Biennial Congress of the European Association of Oral Medicine, Göteborg, Sweden, Aug 24-26, 2000.
https://doi.org/10.1067/moe.2001.112949Get rights and content

Abstract

Objective: The objective of this study was to evaluate the reliability of in vivo staining with toluidine blue in the detection of oral epithelial dysplasia, in situ carcinoma, and invasive squamous cell carcinomas in potentially malignant epithelial lesions (PMELs) and superficial oral ulcerations suggesting malignancy. Study Design: Fifty patients with PMELs and superficial oral ulcerations suggestive of malignancy were selected from those treated at the Oral Medicine Service, Faculty of Dentistry, Araraquara, Brazil. All lesions were submitted to staining with an aqueous solution of 1% toluidine blue, followed by biopsy and histologic analysis. The sensitivity, specificity, and positive and negative predictive values were calculated. Results: Histologic diagnosis revealed that 14% of the lesions analyzed were in situ carcinoma and invasive squamous cell carcinomas, 12% were epithelial dysplasias, 13% were keratosis, 40% were lichen planus, and 8% were other benign lesions. The sensitivity of the staining was 77%, the specificity 67%, and the positive and negative predictive values 43.5% and 88.9%, respectively. Conclusions: Staining with toluidine blue was demonstrated to be highly reliable in the detection of in situ carcinoma and invasive squamous cell carcinoma, because false-negative results for the lesions did not occur. Toluidine blue staining is an adjunct to clinical judgment and not a substitute for either judgment or biopsy. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2001;91:535-40)

Section snippets

Patients and methods

For this study 50 patients with PMELs and superficial oral ulcerations suggestive of malignancy were selected from those treated at the Oral Medicine Service, Faculty of Dentistry, Araraquara, São Paulo, Brazil, from August 1993 to May 1995 (n = 1957). Not included in this study were patients who refused to be submitted to biopsy (n = 21), those who abandoned treatment, or those who had clinically obvious invasive carcinomas or lesions without risk or suspicion of malignancy. Twenty-eight of

Results

Of the 50 patients studied, 34 were smokers (23 smoked paper cigarettes, 7 hand-rolled cigarettes, and 4 pipes), 13 regularly consumed alcohol, and 13 had related occupational activities that frequently exposed them to the sun. The clinical diagnosis of the oral lesions analyzed and the results of staining are presented in Table II.

. Clinical diagnosis of oral lesions and results of staining

Clinical diagnosisn (%)Toluidine blue
+
Homogenous leukoplakia12 (24)210
Nonhomogenous leukoplakia20 (40)1010

Discussion

The sample investigated in this study was composed of 86% PMELs and 14% superficial oral ulcerations suggestive of malignancy, differentiating this work from the majority of previous works, which include in their samples few PMELs and a large number of clinically suspected malignancies or typically benign lesions with no risk of malignancy. Individuals without lesions (control group) were not included in this study, because performance of biopsy in normal mucosa not containing stain retention

Acknowledgements

We are indebted to the “Mario A.S. Paino” Laboratory of Clinical Pathology.

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    *

    Supported by grants CNPq no. 523164/96-3 and FAPESP no. 96/5927-8.

    **

    Reprint requests: Dr Mirian A. Onofre, Departamento de Diagnóstico e Cirurgia, Faculdade de Odontologia de Araraquara - UNESP, Rua Humaitá, 1680, Araraquara - São Paulo, Brazil, [email protected]

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