Abstract

Actinomycosis causes a chronic suppurative infection most commonly involving the cervico-facial region, thorax, and the abdomen. Thoracic infection results from an aspiration of contaminated material from mouth or oropharynx. Actinomyces was known to have a predilection for the periphery of the lung and the endobronchial lesion is extremely rare. We report two cases of actinomycosis presenting as an endobronchial mass which arose in 53-year-old and 44-year-old women. The first case presented with cough, sputum, weight loss and had a history of pulmonary tuberculosis 24 years ago. Chest CT revealed a right lobe collapse simulating mass and suggested carcinoma. The second case presented with hemoptysis for 2 years. Chest CT revealed cystic bronchiectasis of both lungs and intracystic soft tissue mass in the anterior segment of the right upper lobe which suggested aspergilloma. The gross features of them were similar to those of aspergilloma. Characteristic sulphur granules consisting of a granular basophilic center surrounded by a radiating zone of eosinophilic, hyaline, club-shaped projection were histologically confirmed in both cases. Granulomas containing P. westermani eggs were present in the second case. Staphylococcus, true fungal organism, nocardia, and streptomyces shoud be distinguished by analysing their morphologic characteristics in the appropriate stains. Actinomycosis should be included in the differential diagnoses of an endobronchial mass.

• Keywords: Actinomycosis;Endobronchial;Pumonary;