Rapid Immunohistochemistry With Thyroid Transcription Factor-1 for Pulmonary Adenocarcinoma

Background Intraoperative pathologic diagnosis of solitary pulmonary tumors to differentiate between metastatic and primary lung cancer is extremely important to determine the appropriate range of excision. Accurate intraoperative pathologic evaluation may be often difficult, however, and needs additional immunohistochemical (IHC) evaluation to support the diagnosis. Although conventional IHC is a powerful tool for diagnosis, its clinical use is limited intraoperatively because of time constraints. To address this issue, we developed a device that enables complete and rapid IHC (R-IHC) analyses within 20 minutes. We aimed to evaluate the discriminative ability of the R-IHC with anti-thyroid transcription factor-1 (TTF-1) antibody, which is a highly specific IHC marker for primary lung adenocarcinoma. Methods A total of 61 pulmonary tumors that were resected at our institute from May 2011 to September 2013 were retrospectively examined. The samples were sectioned, labeled with anti-TTF-1 antibody using the R-IHC method, and pathologically evaluated. The standard used for evaluation was conventional IHC with TTF-1. Results With the R-IHC procedure, analyses were completed within 20 minutes, with a diagnostic accuracy of 96.7% (59 of 61). Among the 47 primary lung adenocarcinomas, the R-IHC detected 31 (66%) tumors that were positive for TTF-1, with a positive predictive value of 100% (31 of 31). Conclusions Our newly developed method of R-IHC with anti-TTF-1 antibody was useful for diagnosing and differentiation of solitary pulmonary tumors. This technology may prove to be an important supplement to standard intraoperative pathologic diagnosis in routine practice.