[Combined Detection of Thyroid Transcription Factor 1 and Napsin A in Pleural Fluid Cell Blocks Facilitates Cytopathologic Diagnosis of Pulmonary Adenocarcinoma].

Objective To investigate the value of detecting thyroid transcription factor 1(TTF-1) and Noval aspartic proteinase of pepsin family A(napsin A) in pleural fluid cell blocks in cytopathologic diagnosis of pulmonary adenocarcinoma. Methods Conventional cell smears of pleural effusions were obtained from 48 patients with a history of lung adenocarcinoma for cytological analysis. The cell blocks were prepared using the cytological specimens and examined with immunohistochemistry for TTF-1 and napsin A. The rates of a positive diagnosis of pulmonary adenocarcinoma were compared between the two methods, and the diagnositic value of TTF-1 and napsin A in pleural fluid cell blocks was evaluated. Results Immunohistochemistry of the cell block sections yielded a significantly higher positive rate of diagnosis than cytological analysis of conventional cell smear(84.44% vs 55.56%, P0.05). Most of the pleural fluid cell blocks showed positive expressions of TTF-1(36/38, 94.74%) and napsin A(30/38, 78.95%), and none of samples showed TTF-1 or napsin A expression in the mesothelial cells(P0.05). The combination detection of TTF-1 and napsin A in pleural fluid cell blocks had a high diagnosis value with a diagnostic sensitivity of 97.37% and a specificity of 100% for pulmonary adenocarcinoma. Conclusions The combined detection of TTF-1 and napsin A in pleural fluid cell blocks facilitates cytopathologic diagnosis of pulmonary adenocarcinoma.