A high-resolution CT scan demonstrated upper lobe predominant fibrotic changes with architectural distortion, sparing of the bases, and no air trapping (Fig 1)
. Flexible bronchoscopy revealed normal airway anatomy. BAL cytology revealed a mild inflammatory profile, with a nonepithelial BAL cell differential of 70% macrophages, 20% neutrophils, 5% lymphocytes, and 5% eosinophils. Only 2 to 3% of macrophages were estimated to be Oil-Red-O positive. Microbiologic studies were negative. Rheumatologic, immunologic, and general laboratory studies were negative. Erythrocyte sedimentation rate was 1 mm/h, C-reactive protein < 0.1 mg/dL, anti-nuclear antibodies, and rheumatoid factor were negative, and creatine kinase, lactate dehydrogenase, and aldolase levels were normal.