ABSTRACT Empyema originating from a retroperitoneal source is rare due to the anatomical separation between the retroperitoneal and pleural spaces. We report the case of an 81‐year‐old man who presented with pleuritic chest pain following empirical antibiotic treatment for a urinary tract infection. Imaging revealed a large retroperitoneal gas‐containing fluid collection and a left‐sided loculated pleural effusion with a small pneumothorax. Pleural and retroperitoneal collection fluid both grew Escherichia coli suggestive of trans‐diaphragmatic spread. A large hiatal hernia, structural defects of the hemidiaphragm and a Bochdalek hernia may also have been contributing factors. The patient improved with systemic antibiotics, percutaneous drainage of both collections and intrapleural administration of low dose tPA/DNase therapy. This case underscores the importance of considering extra‐thoracic (especially abdominal) sources, especially in patients with structural diaphragmatic abnormalities.
Dhakal et al. (Sun,) studied this question.