Primary endobronchial actinomycosis simulating endobronchial tuberculosis in a patient with diabetes mellitus.

Primary endobronchial actinomycosis is rare and very uncommon without foreign body aspiration. A 70-years old nonsmoker diabetic woman was presented with hemoptysis and weight loss for two months. Fiberoptic bronchoscopy was performed because of hilar mass on her computerized tomography scan, with a presumptive diagnosis of bronchial carcinoma. It demonstrated vegetations in left upper lobe bronchus. Histologic examination of the biopsy specimen demonstrated Actinomyces infection. The patient responded well to penicillin therapy and chest X-ray completely cleared in four months. To our knowledge, the association of endobronchial actinomycosis with diabetes mellitus without presence of a foreign body has not been reported previously, and should be included in differential diagnosis with endobronchial tuberculosis or cancer in endobronchial vegetations.