# Autopsy case report of rapidly progressive iliopsoas abscess caused by Escherichia coli and Prevotella bivia

## TL;DR

A 48-year-old man with a psoas abscess caused by Escherichia coli and Prevotella bivia died despite treatment, highlighting the challenges in diagnosing and managing such infections.

## Contribution

This case report highlights the rare occurrence of a psoas abscess involving Prevotella bivia and Escherichia coli in a hemodialysis patient.

## Key findings

- The patient had a rapidly progressive iliopsoas abscess involving Escherichia coli and Prevotella bivia.
- Computed tomography failed to detect abscesses outside the right pleural cavity, revealed only during autopsy.
- Despite drainage and antibiotic treatment, the patient's condition deteriorated rapidly.

## Abstract

Computed tomography-guided drainage or surgical drainage should be considered for psoas abscesses. Active surgical intervention is considered for gas-forming psoas abscesses; however, computed tomography-guided drainage may be selected, depending on the circumstances. In this case, Computed tomography was used to confirm the spread of the infection, but the autopsy revealed abscess formation outside the right pleural cavity, which was difficult to detect on computed tomography. Prevotella bivia–associated psoas abscesses are rare but have been previously reported.

A 48-year-old male had been undergoing hemodialysis for 5 years for diabetic nephropathy. Contrast-enhanced computed tomography revealed large right-sided predominant abscesses involving the iliopsoas muscle, an abscess with pneumoperitoneum in the para-aortic region, increased density in the perirenal adipose tissue, additional abscess formation, and right empyema. Blood cultures grew Escherichia coli, whereas drainage fluid cultures produced Escherichia coli and Prevotella bivia.

Despite treatment, improvement was minimal, and cardiac arrest occurred on the fourth day after transfer to our hospital.