[A case of pulmonary actinomycosis; histological diagnosis obtained from transbronchial lung biopsy specimen].

We report the first case of pulmonary actinomycosis that was diagnosed by histological findings of transbronchial lung biopsy specimen. A 60-year-old man was admitted because of cough and bloody sputa. His chest roentgenogram and CT scan revealed a cavitary opacity in the apex of the left lung. Histological findings of the biopsy specimen showed multiple basophilic actinomyces granules accompanied by an acute inflammatory exudate, confirming the diagnosis of pulmonary actinomycosis. We prescribed antibiotic treatment and a good response was obtained.