[Value of ThinPrep bronchial brushing cytology in the diagnosis of lung cancers]

To evaluate the ThinPrep bronchial brushing cytology in the diagnosis of lung cancers.

The smear slides of ThinPrep bronchial brushing cytology in 1000 patients collected from April 2001 to April 2002 were reviewed.

Of 389 patients diagnosed as having lung cancer clinically or histopathologically, 273 (70.2%) were revealed by ThinPrep bronchial brushing cytology. Among the 74 patients with benign lung diseases comfirmed by pathology, 3 had been suspected as having lung cancer by ThinPrep bronchial brushing cytology. Actually, they were two patients suffering from tuberculosis and one hamartoma proven by histopathology later. The sensitivity and specificity of ThinPrep bronchial brushing cytology were 70.2% and 95.9%, respectively. Of the 179 patients who had both cytological and histopathological results, the cytology and pathology concordance rate was 95.4% in squamous carcinoma, 87.0% in adenocarcinoma and 95.7% in small cell carcinoma.

Although ThinPrep bronchial brushing cytology has a high specificity, it is not good in diagnosing lung cancer. Poor smearing technique may be responsible for most of the false negative. Type diagnosis of poorly differentiated carcinomas can be difficult when based on the ThinPrep bronchial brushing cytology alone.