A 72-Year-Old Man With Progressive Dyspnea and Diffuse Lung Disease.

A 72-year-old man with progressive dyspnea was referred to our hospital for evaluation of diffuse lung disease. His medical history was unremarkable except for a 20-year history of smoking 20 cigarettes per day. Abnormal findings were first identified on a chest radiograph during a routine medical checkup 11 months earlier. Chest CT scan showed diffuse ground-glass opacities with basilar predominant distribution and some areas of alveolar consolidation predominantly in the lower lobes. Based on clinical and radiographic findings, the patient was initially diagnosed with interstitial lung disease and treated with IV methylprednisolone pulse followed by oral prednisolone, but his condition did not improve. To exclude the possibility of infectious lung disease, empirical antibiotics were administered; however, the patient showed no clinical improvement. Subsequent treatments, including additional methylprednisolone pulses and immunosuppressive agents such as tacrolimus and cyclophosphamide, also failed to yield any significant benefit. His dyspnea progressively worsened, and home oxygen therapy was initiated 4 months before referral. Because of his deteriorating condition despite maximal medical therapy, he was referred to our hospital for comprehensive evaluation.