A 70-year-old male smoker is seen in the clinic with symptoms of cough and sputum production. He is afebrile. On lung exam, there are leftsided crackles and rhonchi with egophony in the LUL. The patient is treated for acute exacerbation of chronic bronchitis. Sputum is negative for AFB. The changes on the patient's CXR on the left side are due to

The PA view of the chest shows marked detion of the trachea into the left hemithorax. The left main stem bronchus is pulled upward, and the left hilum is substantially elevated; the thin, radiodense lines coming from the hilum to the left lower chest are the pulled, stretched pulmonary aeries. There is substantial thickening of the lateral pleural wall, especially in the left upper lobe region. An inhomogeneous density in the left upper lobe region represents bronchiectasis and cystic changes of the destroyed left upper lobe. Although the clinical symptoms are suggestive of chronic bronchitis, the chest radiograph suggests old, inactive granulomatous disease like TB, with pleural-based opacity and loss of volume. Left upper lobe pneumonia does not cause loss of volume unless it is secondary to a necrotizing process.