[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

Immuno- histochemistry 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%, P<0.05). 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 (P<0.05). 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.