Actinomicosis torácica por Actinomyces odontolyticus: A case report and review of the literature

Abstract

Introduction: Actinomycosis is an infrequent infection caused by bacteria from Actinomyces genus that manifests as a chronic, suppurative andprogressive disease. Thoracic actinomycosis occurs in 18% of the cases, and infection by Actinomyces odontolyticus is even less frequent. The clinical presentation mimics tuberculosis or neoplastic processes. Clinical case: We report the case of a 75 years old man with COPD and Diabetes Mellitus type 2. He was referred to our clinic presenting a history of chronic cough, progressive dyspnea, fever and occasional bouts of haemoptysis. Chest radiograph showed a peripherally-located parenchymal opacity in the upper right lobe with over a year of evolution that later became a cavitary mass mimicking bronchogenic neoplasm or tuberculosis. The patient underwent bronchoscopic and CT- guided biopsy that showed necrosis and inflammatory cells. In the culture of cavitary fluids grew Actinomyces odontolyticus. We concluded that it was a thoracic actinomycosis. Penicillin 20 million units per day for six weeks was given, followed by oral amoxicillin for 6 months with good clinical and radiological response. Comments: To our knowledge this is the first report in Chile of lung infection caused by Actinomyces odontolyticus. Actinomycosis is a great masquerader, in this case we made the diagnosis with a fluid culture. This microorganism must be considered in the differential diagnostic in cavitary lung diseases.