Abstract / Summary
Xanthogranulomatous pyelonephritis (XGP) is a rare chronic inflammatory disorder associated with urinary tract obstruction and recurrent infection.Early recognition of XGP is important, as diagnosis is often delayed until significant renal destruction, loss of renal function, and other complications have developed.We report the case of a 36-year-old woman who presented with a three-week history of fatigue, abdominal pain, and markedly raised inflammatory markers.Initial computed tomography (CT) findings were interpreted as pyelonephritis associated with staghorn renal calculi.Following persistent symptoms despite intravenous (IV) antibiotics, multidisciplinary re-review of the imaging identified the characteristic "bear paw" sign of XGP.Ultrasound-guided aspiration isolated Proteus mirabilis, allowing targeted antimicrobial therapy.Despite prolonged courses of IV antibiotics as an outpatient, the patient experienced several relapses requiring readmission, particularly following step-down to oral antibiotics.Stone clearance was attempted twice but was unsuccessful due to difficult anatomy, and complications included perinephric abscess formation requiring ultrasound-guided drainage.The choice of definitive management was complicated by preserved renal function in the affected kidney and the patient's preference to avoid nephrectomy.This case highlights the diagnostic challenges of XGP and the need to consider it in patients with persistent or atypical renal infection, particularly with obstructive calculi.Source control is essential for managing infection but may be complicated by challenging anatomy and the implications of nephrectomy.