Contemporary empyema necessitatis.

Empyema necessitatis is defined by the extension of an empyema through the parietal pleura, into surrounding tissue. Clinical manifestations are generally subacute, representing the indolent nature of the most commonly implicated pathogens (Mycobacterium tuberculosis and Actinomyces israelii). Treatment with antimicrobials and surgical debridement has drastically reduced mortality; however, with proper initial assessment and treatment of pulmonary infection, this rare complication can often be avoided. We describe a patient with empyema necessitatis to illustrate the importance of timely diagnosis and treatment of parapneumonic pleural effusion, and the need to consider this diagnosis in patients presenting with constitutional symptoms and a chest wall mass.