Abstract: TH-PO1124
Hidden in the Shadows: Retroperitoneal Mass Reveals Xanthogranulomatous Pyelonephritis Behind Obstructive Uropathy
Session Information
- CKD: Therapies, Innovations, and Insights
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: CKD (Non-Dialysis)
- 2302 CKD (Non-Dialysis): Clinical, Outcomes, and Trials
Authors
- Uma Dwarakanath, Namitha, Crestwood Medical Center, Huntsville, Alabama, United States
- Pamu, Revanth, Tbilisi State Medical University Faculty of Medicine, Tbilisi, Georgia
- Chen, Yu-Yun C, Crestwood Medical Center, Huntsville, Alabama, United States
- Patra, Tumpa, Crestwood Medical Center, Huntsville, Alabama, United States
Introduction
Xanthogranulomatous pyelonephritis (XGP) is a rare, severe form of chronic kidney infection, can cause renal tissue damage & replacement with granulomatous, fibrotic tissue. It has characteristic yellow, lipid-laden macrophages and was first described in 1916.It has unknown, but chronic UTIs & urinary calculi are commonly involved. Pathogens include E.coli and Proteus . Risk factors are recurrent UTIs,diabetes,nephrolithiasis. Treatment involves antibiotics, drainage, surgery is considered if there is no improvement.
Case Description
A 73-year-old female with a past medical history significant for GERD and endometriosis presented to the ER with a 1 week history of worsening abdominal pain, dyspnea, and fatigue. Review of systems was positive for fever and chills over the preceding few days. On arrival, vital signs were notable for sinus tachycardia (HR 124 bpm) and hypotension (BP 100/51 mmHg). Lab findings showed elevated BUN (43 mg/dL) and creatinine (2.6 mg/dL), anemia (Hb 8.9 g/dL). A non-contrast CT scan of the abdomen and pelvis revealed a large left-sided retroperitoneal mass, left hydronephrosis, hydroureter, and an 11 mm calculus obstructing the left ureter. On admission, the patient received intravenous fluids and was started on ceftriaxone. Urology performed a cystoscopy and placed a left ureteral stent. MRI showed retroperitoneal mass in the left kidney and psoas muscle, suspicious for XGP. Interventional radiology placed a perinephric drain, and cultures grew E.coli sensitive to ceftriaxone. Infectious Disease recommended a total of 14 days of antibiotics.The patient was discharged with a drain and oral antibiotics. 1 month later follow-up CT of the abdomen and pelvis showed a reduction in the size of the mass, with clinical improvement.
Discussion
In rare cases, urinary obstruction could lead to XGP, and often misdiagnosed as malignancy. It involves chronic infection and renal tissue destruction. Common organisms include E. coli and Proteus. It is complicated by sepsis and AKI, was successfully managed with stenting, drainage, and antibiotics. Nephrectomy is the standard treatment in most cases. Initial treatment with multidisciplinary approach are essential to reduce morbidity and preserve renal function.