Otolaryngology, Head and Neck Surgery
Objective: To use toluidine blue intra-operatively to identify tumour involved margins after the removal of oral cavity squamous cell carcinoma, and to compare the findings with those of final histopathology.
Methods: The study was conducted at the Aga Khan University Hospital from December 1, 2009, to March 14, 2010, and comprised 56 consecutive patients with biopsy-proven squamous cell carcinoma of oral cavity regardless of grade and stage of tumour. Intra-operatively toluidine blue was used on the resected tumour margins and the staining patterns were assessed. Results were then compared with the final histopathology report.
Results: A total of 11(19.64%) margins were positive with toluidine blue staining out of which 8 (14.28%) were false positive. Sensitivity and specificity was found to be 100% and 84.9% respectively with a positive predictive value of 27.2%; a negative predictive value of 100%; and diagnostic accuracy of 85.71%.
Conclusion: Toluidine blue costs only Rs25 (USD 0.30) and takes only 5 minutes for application and interpretation. It can be used with significant confidence in smaller lesions (T-I and T-II) as an alternative to frozen sections in developing countries where facilities are unavailable. Its use in larger lesions (T-III and TIV) remains the topic of controversy and awaits a multi centre trial with a larger cohort.
Journal of the Pakistan Medical Association
Ali, N. S.,
(2013). Toluidine blue: Yet another low cost method for screening oral cavity tumour margins in Third World countries. Journal of the Pakistan Medical Association, 63(7), 835-837.
Available at: http://ecommons.aku.edu/pakistan_fhs_mc_surg_otolaryngol_head_neck/47