Conventional respiratory cytology versus fine needle aspiration cytology in the diagnosis of lung cancer.

The results of 184 fine needle aspiration (FNA) cytologic examinations were compared with the findings of "conventional" respiratory cytology (on sputums, bronchial brushings and bronchial washings) and histology (on biopsy and autopsy samples) and with the medical records. Positive cytologic results were obtained in 6 (10%) of 60 sputums, 17 (21%) of 80 brushings, 16 (19%) of 84 washings and 82 (44%) of 184 aspirates. These positive results were confirmed by biopsy for 6 of 6 sputums, 16 of 17 brushings and 15 of 16 washings. Among the 82 patients with a positive FNA cytology, malignancy was confirmed by lung biopsy in 39 and by autopsy in 2; the cytologic diagnosis was supported by clinical and radiographic findings in all but 1 of the remaining 41 patients. Using transbronchial lung biopsy, autopsy and medical records as final standards, the positive predictive values were 100% for sputum, 94.1% for brushings, 93.0% for washings and 98.6% for FNA samples. The high positive predictive values of FNA and the other cytologic procedures indicate that these diagnostic modalities provide simple, rapid and reliable methods for the diagnosis of lung cancer.