Retroperitoneal abscess perforating into the thoracic cavity in an immunocompromised host

Abstract

A 71-year-old man with a retroperitoneal abscess caused by a ureteral stone was successfully treated by retroperitoneal drainage. He was considered to be at high risk of infection because of his bedridden state (resulting from a post-cerebral infarction and malignant rheumatoid disease) and steroid administration for the rheumatoid disease. He also had an empyema adjacent to the retroperitoneal abscess. This was thought to be separate from the retroperitoneal abscess because it did not resolve after the retroperitoneal drainage. Thoracic cavity drainage was undertaken, after which the empyema disappeared. The drainage fluid contained pus, similar to the fluid from the retroperitoneal drainage. Escherichia coli organisms were cultured from both drainage fluids. There were no signs of recurrence on computed tomography (CT) imaging. In conclusion, we report a case of retroperitoneal abscess perforating into the thorax, successfully treated by retroperitoneal and thoracic cavity drainage in an immunocompromised host. CT was a very effective imaging modality for this diagnosis, and we recommend early drainage of abscess in immunocompromised patients.