Case: A 51 year old African American Man without significant past history presented with three weeks of persistent cough productive of copious yellow sputum. He denied fevers, chills, hemoptysis, dyspnea, weight or appetite changes, sick contacts, recent travel. On physical examination, the patient was afebrile and appeared comfortable. He had decreased air entry of the left lower lobe with dullness to percussion. A 5x3 cm fluctuant mass was incidentally found on the left anterior chest wall at the level of the 11th rib with yellow expressible exudate at which time the patient reported a minor trauma sustained 3 weeks prior. WBC count was 17,300/mcL. CT chest identified a peripherally enhancing fluid-attenuation structure in the left lower lung measuring 11.8 cm x 11.3 cm x 9.6 cm. The collection appeared to be tracking out from the pleural space to the exterior skin that corresponded to the site of the chest wall swelling. There was also a focal lytic lesion of the adjacent ribs. He was empirically started on Vancomycin, clindamycin and piperacillin-tazobactam. CTguided aspiration failed because the material was too viscous to be aspirated; a chest tube drained copious yellow exudate. Blood cultures and respiratory cultures were negative. Gram stain of the purulent material demonstrated clusters of branching gram positive rods. Pathology showed necrotic debris with clusters of filamentous gram negative organism. Acid fast and Kinyoun stains were negative. He was started on empiric Penicillin G for empyema necessitans with a presumed etiology of actinomyces. Due to development of hypersensitivity drug eruption from PCN, intravenous doxycycline was started for total of 14 days followed by 6 months of oral therapy. Imaging four weeks after treatment showed significant reduction in size of the lesion. Culture confirmed Actinomyces israelii.
Discussion: Actinomyces are anaerobic gram positive commensals of the oral cavity notorious to breach though tissue planes. Thoracic manifestations are varied and can mimic malignancy. Astute microbiology and pathology tests are necessary to make an early diagnosis and prevent invasive surgery as the organism is a slow growing anaerobic bacteria. Excellent clinical and radiologic response were noted in our case following treatment with chest wall drainage and antibiotics thus avoiding invasive thoracic surgery.