LAUSR

A 40-year-old man presented to the emergency department with an oxygen saturation of 89% with on ambient air, fever (38.6 °C), and reduced air entry in the right hemithorax upon auscultation. His medical history included quadriplegia, hydrocephalus, and a ventriculoperitoneal shunt following traumatic C4 cervical vertebra injury. A computed tomography scan revealed a right supra-renal abscess with suppurative damage to the renal parenchyma caused by an obstructing calculus (yellow arrow). It also revealed right pleural empyema and focal discontinuity of the posterior hemidiaphragm (white arrow) which was identified as the possible location of continuity between the retroperitoneum and the right pleural cavity (Fig. 1). Thoracic drainage yielded 5000 ml of purulent fluid. Cultures of the pus grew Proteus mirabilis and the patient was treated with piperacillintazobactam. The renal abscess was drained, and a percutaneous nephrostomy was placed. The patient improved and was discharged breathing ambient air after 21 days of hospitalization. This rare case highlights how Proteus mirabilis empyema originating as pyonephrosis may develop into complicated thoracic infection via pleural access.