Further Appraisal of in Vivo Staining Properties of Oral Cancer

INITIAL reports were made by Niebel and Chomet,¹Spengos,²and independently from this laboratory³of the fact that the topical application of toluidine blue, an acidophilic, metachromatic nuclear stain, can be used in the in vivo evaluation of neoplastic change in oral mucous membrane. Areas of carcinoma in situ or invasive carcinoma have a strong affinity for the dye, whereas normal mucosa does not. This response permits detection of small, early lesions and their surface delineation. The initial report from this institution included 23 patients with various forms of epidermoid carcinoma. In view of the considerable interest manifested by medical and dental groups in this property of oral neoplasia, this further appraisal of results is presented covering patients studied since the time of the earlier report. The lesions under study fall somewhere in the following histologic spectrum: (1) normal epithelium; (2) dysplasia, moderate; (3) dysplasia, severe; (4)