pulmonary actinomycosis mimicking lung cancer

herein, we reported on a case of solid type of pulmonary actinomycosis in a 10-year-old boy. he had productive cough for 40 days. bronchoscopy was normal. cmputed tomography revealed a solid large mass in the upper lobe of his left lung with mimicking malignant leisions. he was referred for surgery and underwent left upper lobectomy. macroscopically, the specimen measured 13×9×5 cm and was creamy to whitish on cut section. microscopic findings included a large number of inflammatory cells and colonies of actinomyces. pulmonary actinomycosis should be included in the differential diagnoses of pulmonary mass lesions, especially in the young adults.