[Pulmonary actinomycosis developing diffuse phregmone after pneumonectomy].

The patient was a 75-year-old male who consulted the department of respiratory tract internal medicine in our hospital for left chest pain occurring from the beginning of December 2003. Chest X-ray indicated a tumorous shadow in the left lower lung field. A chest CT also revealed an irregularly shaped mass shadow in the left lower lobe. Since bronchoscopy failed to establish a definitive diagnosis, the patient was referred to our department for surgery to undertake thoracotomy. After left pneumonectomy being performed based on a suspicion of lung abscess, pathological examination of specimen from the resected left lung showed sulfur granules which led to the diagnosis of pulmonary actinomycosis. Because of the diffuse phregmone developing around the surgical wound, benzylpenicillin potassium administration was started, and was continued for a further 6 months on an outpatient basis. Pulmonary actinomycosis is a relatively rare chronic pulmonary infection. It is often difficult to distinguish pulmonary actinomycosis from other pulmonary disease such as lung cancer because of the similarity of their appearance on X-ray or CT, and almost all cases of pulmonary actinomycosis are diagnosed by thoracotomy.