Cytological diagnosis of lung cancer in Chiang Mai, Thailand: cyto-histological correlation and comparison of sensitivity of various methods.

To evaluate the role of cytology of sputum, bronchial brushing (BB), bronchial washing (BW), bronchoalveolar lavage (BAL) and fine needle aspiration cytology (FNA) in the diagnosis of lung cancer using histological material as a gold standard, a retrospective study was performed on cytological materials obtained from 243 patients with possible lung cancer. Of these, 160 had been confirmed histologically to have lung cancer. Cytological materials included in the study were 31 sputa, 123 BWs, 11 BBs and 36 BALs. Meanwhile, FNAs and concurrent gun biopsies (GBs) were performed on 23 patients clinically and histologically proved to have lung cancer. The overall sensitivity of sputum, BW and BAL was 0.222, 0.455 and 0.361, respectively. BB provided a significantly far superior sensitivity (0.800) than those of three former methods with p<0.05 by Fisher's exact test. FNA and GB seemed to provide greater sensitivity of 0.913 and 0.783, respectively. Although the complimentary role of various conventional cytological techniques is well recognized, bronchial brushing is the only single technique that significantly improved diagnostic yield. FNA and GB techniques should be encouraged due to their superior sensitivity.