The role of toluidine blue in assessing margin status after resection of squamous cell carcinomas of the upper aerodigestive tract

Objectives: To determine the efficacy of toluidine blue in assessing margin status after removal of squamous cell carcinomas of the upper aerodigestive tract. Design: A prospective study of 50 consecutive patients undergoing surgical resection of squamous cell carcinomas of the upper aerodigestive tract was performed during February 1 to December 1, 1993. After tumor resection, toluidine blue was applied directly to the remaining unresected mucosa. The staining characteristics of the mucosa were then compared with those of frozen-section biopsy specimens of the margins and with the permanent histologic findings of the resected tumor specimen. Results: In three cases, toluidine blue identified a positive margin, which was confirmed on frozen and permanent section. In six cases, false-positive staining was noted, which was most frequently related to traumatic handling of the mucosa during the resection. In no case was a positive margin found on histologic staining that failed to stain with toluidine blue. During routine staining of surrounding unresected mucosa, three cases of a second primary tumor that was not seen on routine evaluation before tumor removal were identified with toluidine blue. In one case, a second Tl oral cavity lesion was found, while in the other two cases, separate pharyngeal lesions were identified. Conclusions: Based on these findings, it appears that toluidine blue improved the ability to assess margin status at the time of resection, and we advocate its use after resection of tumors of the upper aerodigestive tract.