A rare case of bacterial translocation from a renal abscess resulting in empyema necessitans: a case report and literature review

Empyema necessitans (EN) is a rare complication of thoracic empyema in which infection spreads into the chest wall. While historically associated with tuberculosis, EN caused by <i>Escherichia coli</i> is exceedingly rare. Our report highlights a case of EN in a 76-year-old male that developed after dislodgement of a chest tube placed for the treatment of a pleural effusion associated with a perinephric abscess. The patient presented with a cough and chest wall bulge and admission imaging confirmed a loculated pleural effusion with extension into the chest wall. Cultures from a spontaneously draining pleurocutaneous fistula grew <i>E. coli</i> and the patient required surgical intervention for decortication and excision of the fistula tract. This case highlights the importance of considering extra-thoracic sources of infection in empyema, maintaining suspicion for EN in patients with a history of inadequate drainage, and the role of early surgical intervention in preventing complications.