A chest radiograph should be obtained when a patient with cough has risk factors for lung cancer or a known or suspected cancer in another site that may metastasize to the lungs. A CT scan of the chest is often needed to further characterize abnormalities that are seen on the plain chest radiograph. Occasionally, a central airway cancer will be not visible on a plain chest radiograph, yet will be quite evident on assessment of the airways via CT imaging or at the time of bronchoscopy. Precise data are not available for the increased yield from CT imaging over plain chest radiographs for central airway tumors that are endoscopically visible, but are not visible on the plain chest radiograph. fully
Cytologic examination of spontaneously expectorated or induced sputum may provide a definitive diagnosis of lung cancer. However, bronchoscopy is usually indicated when there is suspicion of airway involvement by a malignancy. Shure found completely obstructing lung cancers in the central airways (segmental or larger) in 36 of 81 endobronchial lesions (44%) with no radiographic signs of obstruction. The chest radiograph findings were normal in 13 patients (16%). All 13 patients had risk factors for and symptoms suggestive of bronchogenic carcino-ma. Thus, for a smoker who has both cough and hemoptysis that persist after antimicrobial treatment for bronchitis, bronchoscopy is indicated even when the chest radiograph finding is normal.
The findings from a bronchoscopic inspection of the airways may guide the choice of treatment options, some of which are likely to improve the cough and often the associated dyspnea. The accompanying postobstructive pneumonia may be more easily understood by the findings at bronchoscopy, and relief of the pneumonia may follow specific treatment that is aimed at relieving the obstruction.