ABSTRACT
Pulmonary actinomycosis is rarely reported in pediatric age. An 11-year-old girl with history of two-month back pain was admitted to our hospital. On physical examination respiratory sounds were diminished on the left upper lung. Chest radiograph revealed a mass in the left upper lobe. Computed tomography showed solitary lesion (5.6 x 4.5 cm in size) in the left upper lobe. We could not rule out the possibility of malignant thoracic tumor. The patient underwent surgery. Histological examination of the resected tissue revealed, numerous sulfur granules, characteristic of Actinomyces, surrounded by purulent exudates, which are consistent with actinomycosis. She was treated with penicillin G. The patient responded well to penicillin therapy and the lesions regressed completely. She remained well throughout the three-year follow-up.