Comparative study of toluidine blue and hematoxylin and eosin staining in evaluating skincarcinoma during Mohs micrographic surgery

Introduction: Mohs micrographic surgery is a specialized surgical technique used to treat nonmelanoma carcinoma. Histopathology plays a vital role in the diagnosis of this condition, and the choice staining method is controversial. Objective: to compare results in the use of hematoxylin and eosin (H&E) versus Toluidine blue (TB) staining during surgery. Method: observational, descriptive and transversal study conducted from November, 2017 until May, 2018 of the slides used during surgeries in the selected period. Slides were analysed by the Mohs surgeon, 3 residents and a dermopathologist to evaluate the results of both staining methods, in consideration of cell features and stromal elements. Results: 23 tumors were analysed (16 Basal Cell carcinomas and 7 Squamous Cell Carcinoma). Microscopic observation of slides prepared with Toluidine blue and hematoxylin and eosin stains did not show significant global differences between both groups, except in terms of a few characteristics, in particular with hematoxylin and eosin stains. Conclusions: this was the first study in Uruguay to evaluate the effectiveness of both staining methods during Mohs micrographic surgery, and it concluded that both Toluidine blue and hematoxylin and eosin stains are very good techniques in evaluating skin-cancer.