For the past 3 months, a 66-year-old man has suffered fatigue and loss of appetite and weight. He was not coughing, nor had he experienced fever, chest pain, or hemoptysis. He had no history of notable respiratory disease, and he was not aware of having had tuberculosis (TB).
The patient had smoked a pack of cigarettes daily for 40 years but stopped smoking 6 years ago. He did not drink alcohol and had no risk factors for HIV infection.
Except for a temperature of 36.8°C (98.2°F) and signs of right upper lobe consolidation and possible collapse, physical examination results were unremarkable. Hyponatremia was the only laboratory test abnormality.
A chest film confirmed right upper lobe consolidation and also showed compensatory emphysema and elevation of the right hilum without tracheal shift (A). Because this was a marked collapse, the density of the lobe blends with that of the right superior mediastinum. CT of the chest revealed consolidation with partial collapse of the right upper lobe and an air bronchogram with cavitation or bronchiectasis (B and C). No masses were detected.
Examination of induced sputum showed acid-fast bacilli. Sputum cultures grew Mycobacterium tuberculosis. The patient was treated with four TB medications and showed good clinical and radiologic response.
Air bronchogram is usually associated with alveolar lesions, such as an inflammatory process, infarct, contusion, alveolar cell carcinoma, or lymphoma. Its presence without cavitation or bronchiectasis, however, may radiologically simulate pyogenic bacterial pneumonia. In this case, clinical data and further investigation should be applied to diagnose the underlying entity.