A retroperitoneal abscess is a collection of pus in the retroperitoneal space.

These abscesses may occur as the result of hematogenous seeding in the setting of bacteremia (eg, in the case of psoas abscesses), by contiguous spread, perforated viscus, or as a complication of pancreatitis or pyelonephritis.

Patients may present acutely or subacutely depending on the etiology of the abscess. Typical symptoms include fever and back or pelvic pain. A lumbar mass can sometimes be appreciated. Urinary symptoms may be present in the case of a renal abscess.

Risk factors for this infection depend on the etiology of the abscess. Patients with diabetes or who are immunosuppressed are at increased risk. Previous urologic surgery is associated with renal abscess.

Related topic: Perinephric Abscess