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

## TL;DR

A rare case of empyema necessitans caused by Escherichia coli is reported, originating from a renal abscess and requiring surgical treatment.

## Contribution

This case report adds to the limited literature on EN caused by E. coli and emphasizes the importance of considering non-tuberculous sources.

## Key findings

- Empyema necessitans was caused by E. coli, not tuberculosis, in a 76-year-old male.
- The infection originated from a perinephric abscess that spread to the pleural cavity and chest wall.
- Surgical intervention was necessary to manage the pleurocutaneous fistula and prevent complications.

## Abstract

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 Escherichia coli 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 E. coli 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.