[A case of chronic pigeon breeder's disease accompanied with progressive pulmonary cysts and recurrent pneumothorax].

We followed up a case of chronic pigeon breeder's disease with progressive pulmonary cysts and recurrent pneumothorax. The patient was a 48-year-old man who started to breed pigeons 14 years ago. He was diagnosed 7 years ago as having hypersensitivity pneumonitis due to pigeons, but he refused to stay away from the birds until he experienced episodes of dyspnea on exertion 3 years ago. A chest CT scan showed multiple cysts and peribronchial fibrosis in both lungs. The pathological findings of video-assisted-tracheoscopic surgery showed a centribronchial granuloma with lymphocyte infiltrations. Tests for antibodies against pigeon extracts of droppings were positive. Even after steroid treatment and avoidance of pigeons 3 years ago, there have been progressive cysts and fibrosis in the lungs. Progressive pulmonary cysts with recurrent pneumothorax is a rare manifestation as a chronic pigeon breeder's disease.