Diagnostic value of differential brushing of all branches of the bronchi in patients with sputum positive or suspected positive for lung cancer.

In roentgenographically occult lung cancer, it is often difficult to determine the location of the tumor despite the existence of cancer. This complicates diagnosis and points to a need for a more systematic method of examination. Differential brushing was performed on all the respective segmental bronchi in both lungs of 196 patients with positive or suspected positive indications of lung cancer as revealed by sputum cytology. Fifty-nine borderline lesions in 43 cases and 107 lung cancer lesions in 95 cases were diagnosed. Localization was possible in 70.4% of the cases. The diagnosis of borderline lesions was also possible. At the first examination, the rate of localization, as compared with that in the historical control group, improved from 64.1% to 95.8%, and, in particular, an improvement from 0% to 86.2% was noted in those cases in which abnormal bronchoscopic findings were not observed. Concurrent multiple primary cancer was also diagnosed in 12.6% of lung cancer cases before treatment. With this method, cytologic findings in sputum and in specimens obtained by brushing and histologic findings of resected lung can be compared in an integrated manner, and henceforth more accurate diagnostic criteria can be established.