[Lung abscess which ruptured during the medical treatment of lung abscess; report of a case].

63-year-old man was admitted to our hospital with fever and cough for about 2 months. Laboratory data showed marked inflammatory changes, and chest computed tomography (CT) scans revealed right-sided hydrothorax, atelectasis of the right middle lobe, and a cystic mass in the right middle lobe. We diagnosed the patients as having lung abscess and empyema. Following the intravenous antibiotic chemotherapy, symptoms and laboratory data showed the improvement, however, on the 11th hospital day, he developed high fever again. A chest CT showed pneumopyothorax suggesting the rupture of lung abscess. Since the chest tube drainage was ineffective, open chest surgery was performed. Curettage of both thoracic and abscess cavity with closure of air leakage successfully cured the pyothorax.