Endobronchial actinomycosis simulating bronchogenic carcinoma. Diagnosis by bronchial biopsy.

Five cases of actinomycosis of the main bronchi or trachea which were suggestive clinically of bronchogenic carcinoma are described. In four patients the correct diagnosis was made by a bronchial biopsy or wash, or both. Three of them recovered following antibiotic treatment, and one died a few days after bronchoscopy. In one case the Actinomyces were found in the bronchial wash retrospectively following diagnosis of pulmonary actinomycosis in the lobectomy specimen. A concomitant endobronchial lipoma was found in one of the patients. The diagnosis of pulmonary actinomycosis by bronchial biopsy may save the patient major surgical intervention.