Diagnostic problems of cancer of the lung.

There are three techniques of primary significance to the diagnostic problems of cancer of the lung. Roentgenologic evidence is suggestive but not conclusive unless confirmed by other means. Because pulmonary cancer masquerades, morphologic proof is needed. In some cases bronchoscopy can provide proof, but its usefulness is limited to lesions in the major bronchi. For the third technique, cytologic study, to be effective, apparently it is necessary only that there be a free passageway between the trachea and the tumor body. Cytologic studies were carried out in 2,066 cases of all types of diseases of the chest. In 241 of these cases bronchogenic carcinoma was proved by one means or another; the presence of cancer was diagnosed by cytologic methods in 55 per cent of the 241 cases. When five specimens of sputum from each patient were examined, the efficiency of the technique rose to 90 per cent. Wider application of this simple and relatively inexpensive technique may greatly aid in the solution of diagnostic problems of pulmonary cancer.