摘要:A case is presented of pulmonary botryomycosis in a 61-year-old man with a massive right-side pulmonary infiltrate which looked like a tumor (on X-ray). Microscopic examination of a transbronchial biopsy specimen revealed chronic suppurative inflammation, which did not regress despite intensive antibiotic therapy for a period of two months. Histological analysis of specimens taken during surgery for hemoptysis revealed pulmonary botryomycosis. The disease was diagnosed on the basis of characteristic eosinophilic granules in which the bacteria are surrounded by protein material (Splendore-Hoeppli phenomenon). Pulmonary actinomycosis was excluded. The case demonstrates that pulmonary botryomycosis can have the appearance of a mass which resembles pulmonary carcinoma on X-ray, and may also be mistaken for pulmonary actinomycosis. For this reason, pulmonary botryomycosis, although rare, should be excluded during differential diagnosis of hemoptysis or pulmonary infiltrates.