A 31 y.o. male had a previous gsw to the R chest and notes a mass on the chest wall.
What is it?
Our patient had empyema necessitans which is a complication of poorly controlled empyema where a collection of purulent material forms a fistula between the pleural cavity and the skin. In the case of our patient his gunshot wound though the liver and into the chest caused an empyema which was not adequately drained and extended to the skin. While Strep pneumo is the most common bacterial infection to cause this type of fistula; Proteus, E. coli, and Nocardia have been associated as well. While common bacterial infections are more likely to be seen in the US, tuberculosis is the leading cause of empyema necessitans world wide. In the developing world the diagnosis of tuberculosis can be difficult since malnutrition may be present and this causes anergy— a negative skin test. The diagnosisin cases of malnutrition is made by culture of the drainage.
empyema necessitans in tuberculosis
Another cause of empyema necessitans is Actinomycosis. Actinomycetes are prokaryotic bacteria (originally thought to be fungi) which were first shown to cause human disease in 1857. The word actinomycete is derived from the Greek term aktino which refers to the radiating appearance of the sulfur granules they contain. A fistula from Actinomycosis to the skin can be diagnosed by the presence of these granules .
sulfur granules seen with PMNs under a microscope.
Francis A, Donald E, Eric S. Pleural effusion and empyema in paediatric surgery: a comprehensive text for Africa. in Ameh Z, Bichler S eds.pp 209-303. Global Health Organ Seattle Wa USA 2010
Akqul A, Orki A, Orki M, et al. Approach to empyema necessitatis2011. World Journal of Surg Vol 35 no 5 pp981-984.
Kellie S, Shaib F, Forster D. Empyema necwssitatis. Chest .2010. vol 138, article 39A.
Yauba M, Ahmed H , Imouan M , et al. Empyema necessitans complicating pleural effusion associated with proteus species. 2015. Case Reports in Pediatrics Article ID 108174 https:// doi.org/10.1155/2015/108174.