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Kidney Week

Abstract: TH-PO603

Rare Type of Pyelonephritis

Session Information

  • Trainee Case Reports - II
    October 25, 2018 | Location: Exhibit Hall, San Diego Convention Center
    Abstract Time: 10:00 AM - 12:00 PM

Category: Trainee Case Reports

  • 1902 CKD (Non-Dialysis): Clinical, Outcomes, and Trials


  • Madani, Mohammad, Aurora St. Luke's Medical Center, Milwaukee, Wisconsin, United States
  • Schmidt, Joseph, Aurora Medical Group, Wauwatosa, Wisconsin, United States

Xanthogranulomatous pyelonephritis (XGP) is a rare chronic destructive granulomatous inflammatory process of renal parenchyma accounting for 0.6% of histologic cases of chronic pyelonephritis. Exact etiology is unknown however this process is associated with long term obstruction and infection. The aim of this case report is to enhance awareness of this rare condition in an effort to prevent delayed treatment and adverse outcomes.

Case Description

A 69 year old woman presented with left hip and flank pain of 3 weeks duration. Vital signs were as follows: temp 98.5, 104 HR, 16 RR, BP 133/64. Physical exam revealed left costovertebral angle tenderness. Labs were notable for leukocytosis WBC 16.5, hemoglobin 8.4, hematocrit 26.9, MCV 83.5, creatinine 1.7, BUN 18 mg/dL. Urinalysis revealed >100 WBCs, positive nitrite, moderate leukocyte esterase.

She underwent CT scan of the abdomen pelvis which revealed severe cystic replacement of left renal parenchyma, perinephric inflammatory changes, left ureteral calculus distal to the left UPJ, and left psoas muscle fluid collection (figure). IV antibiotics and pain medication were given. A nephrostomy tube and drain was placed with cultures showing E coli. She remained afebrile and had satisfactory drain outputs. She underwent left radical open nephrectomy and adequate postoperative recovery. Specimens showed no distinct corticomedullary junctions, granulomatous inflammation and cholesterol clefts.


Clinical presentation of XGP may be vague. Its diffuse or advanced stage typically requires nephrectomy. Antibiotics may be used for treatment of focal or bilateral XGP. In summary, this case highlights many features characteristic for a rare type of chronic pyelonephritis with associated psoas abscess complication. Maintaining a high index of suspicion for this condition leading to an accurate and earlier diagnosis may influence prognosis.