[A case of idiopathic interstitial pneumonia with pneumothorax and pneumomediastinum, accompanied by rapid progression of cystic changes on CT].

A case of idiopathic interstitial pneumonia (IIP) with pneumothorax and pneumomediastinum was presented. A 52-year-old male was admitted with the complaint of cough, fever and dyspnea. Chest roentgenogram revealed bilateral reticulonodular shadow and right pneumothorax. Radiological, laboratory and clinical findings were consistent with the diagnosis of acute exacerbation of IIP. Repeated chest CTs showed diffuse interstitial opacities and the presence of pneumothorax and pneumomediastinum. Furthermore, honeycombing and bullous change progressed markedly for two months. The mechanisms of pneumothorax and pneumomediastinum were speculated to be due to the rupture of those cystic lesions which had grown rapidly on follow-up CTs. It was suggested that the formation of honeycombing occurred within a few months and the increasing of honeycombing might be accompanied by so-called acute exacerbation of IIP. We propose that follow-up CTs were useful for the chronological study for interstitial lesions of IIP.