Pulmonary actinomycosis is a rather rare chronic pulmonary infection. Its diagnosis may be difficult without biopsy, because its culture from sputum or bronchial secretion is rarely successful. We report a case of pulmonary actinomycosis diagnosed by means of TBLB. A 57-year-old man was admitted to our hospital because of hemosputum. The chest radiograph at the first visit revealed a nodular lesion in the right middle lobe. The biopsy examination showed sulfur granules of which PAS-positive mycelium was arranged in a radiating pattern. On the basis of these findings, we diagnosed pulmonary actinomycosis. So far, there have been only 4 reported cases of pulmonary actinomycosis diagnosed by TBLB in Japan. TBLB is worth trying in the diagnosis of pulmonary actinomycosis, because it can avoid surgical procedures, if successful.
