Usually results from rupture of an acute cortical abscess in the perinephric space or from haematogenous seeding from other sites of infection

Aetiology

• Pyrexial
  • ~33% not pyrexial - usually chronic abscess
• Flank mass in 50%

Investigations

• Bloods: high WCC, high serum creatinine
• Urine: pyuria
• CT

Management

• Antibiotics and percutaneous or surgical drainage