[A case of acute progressive pulmonary cystic disease associated with Pneumocystis carinii pneumonia in a non-HIV-infected patient].

: We report a case of Pneumocystis carinii pneumonia (PCP) in which acute lung tissue destruction progressed within a few days to form multiple bullae in a patient with no HIV-1 infection. A 59-year-old man with mild pulmonary emphysema had been followed for two years. He had smoked 40 cigarettes per day for forty years. Six months before, bronchogenic carcinoma had been diagnosed in the lower right lung. After chemotherapy and radiotherapy, he had a sudden onset of high fever with respiratory failure. PCP was diagnosed by examination of the bronchoalveolar lavage fluid (BALF), and the patient was treated with intravenously administered trimethoprim-sulphamethoxazole (TMP-SMX) and methylprednisolone. His chest radiograph was not typical for PCP, and showed no diffuse ground-grass or fine granular opacities. A high-resolution CT of the chest revealed a low attenuation area consistent with severe emphysematous alterations and progressively enlarging bullae. A few cases have been reported of progressive pulmonary cystic disease associated with PCP pneumonia in patients with AIDS, in which the cause of bulla formation was thought to be lung parenchyma destruction induced by HIV itself, or increased elastase release from HIV-infected macrophages. The present case demonstrated that HIV infection was not an essential factor in the development of bullous changes. In a patient with a long history of smoking and emphysema, PCP may trigger-macrophage activation and an excessive release of leukocyte elastase, leading to elastin destruction in the alveoli.