History A 31-year-old woman with a history of bilateral orthotopic lung transplantation performed 10 months earlier for cystic fibrosis presented for a routine follow-up appointment, with her chief symptom being a cough. The cough started approximately 1 month prior to this appointment and was minimally productive of clear to yellow phlegm. In addition to her cough, she reported increased sinus congestion and a sensation of “something in her upper chest.” She denied shortness of breath, wheezing, hemopty-sis, or cigarette smoking. Review of systems was negative for fever, chills, or night sweats. At physical examination, the patient was afebrile, borderline tachycardic (heart rate, 99 beats per minute), and mildly hypertensive (blood pressure, 138/99 mm Hg). Oxygen saturation was 96% on room air. Laboratory evaluation revealed a white blood cell count of 3.5 × 109/L (normal range, 3.2–9.8 × 109/L). Pulmonary function testing was notable for a newly decreased ratio of forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) of 64% (2.0 and 3.4 L, respectively) (normal FEV1-to-FVC ratio, 80%), suggesting an obstructive lung process. One month prior to presentation, the patient’s sputum cultures grew Pseudomonas and methicillin-resistant Staphylococcus aureus. The patient showed no evidence of active infection at the time of Bron-choscopy. Thus, the bacteria were favored to reflect colonization, and antibiotic therapy was not administered at that time. The patient was taking an immunosuppression regimen of mycophenalate mofetil (CellCept; Genentech, San Francisco, Calif) (1 g twice daily), prednisone (10 mg daily), and tacrolimus (Prograf; Astellas Pharma US, Northbrook, Ill) (goal therapeutic range, 12–14 ng/mL). The patient was sent for posteroanterior and lateral chest radiography followed by chest CT (Figs 1–3) and fluorine 18 fluorodeoxyglucose PET/CT (Fig 4).