Abstract: TH-PO1114
Foam Cells and Fistula: The Aggressive Spectrum of Xanthogranulomatous Pyelonephritis
Session Information
- Pathology and Lab Medicine
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Pathology and Lab Medicine
- 1700 Pathology and Lab Medicine
Authors
- Islam, Nayeemul, Sir Salimullah Medical College, Dhaka, Dhaka Division, Bangladesh
- Sultana, Syeda Salima, New York City Health and Hospitals South Brooklyn Health, New York, New York, United States
- Anjum, Nazifa, Sir Salimullah Medical College, Dhaka, Dhaka Division, Bangladesh
- Misha, Maisha Maliha, Sir Salimullah Medical College, Dhaka, Dhaka Division, Bangladesh
- Lopez, Mark Joseph Cerna, New York City Health and Hospitals South Brooklyn Health, New York, New York, United States
- Lee, Winston, New York City Health and Hospitals South Brooklyn Health, New York, New York, United States
Introduction
Xanthogranulomatous pyelonephritis (XGP) is a destructive, unusual and rare type of chronic granulomatous renal infection which is typified by progressive parenchymal destruction and replacement with lipid-filled foamy macrophages. It causes about 0.6 to 1 percent of renal infections and it is usually manifested in middle-aged women who develop urinary symptoms and urolithiasis. We describe a unique case of diffuse XGP with extra-renal spread in the form of a psoas abscess in an older male without typical urinary symptoms.
Case Description
A 71-year-old man with a history of hypertension, hyperlipidemia, and previous partial gastrectomy reported with generalized weakness and 6-7 weeks of intermittent fever. Computed tomography with contrast medium showed a large left retroperitoneal/psoas abscess that communicates to an enlarged left kidney and exhibits numerous hypodense calyceal collections and the typical bear-paw appearance. The culture of urine was negative, and abscess fluid produced pan-sensitive Escherichia coli. The management involved initial use of broad-spectrum intravenous antibiotics and CT-percutaneous drainage. Repeat imaging led to the suspicion of constant symptoms and reduced drain output, indicating possible underlying XGP. The patient then received a left nephrectomy, and histopathology revealed the presence of diffuse XGP (stage III, Malek and Elder classification). He had been released on a long-term prescription of culture-specific antibiotics and with good clinical improvement.
Discussion
This case underscores the need to take into consideration XGP in patients with prolonged constitutional symptoms and retroperitoneal collections despite the lack of urinary results. Early identification, recurrent imaging in non-resolving instances, and surgery with good time is a prerequisite to good results
Coronal CT shows persistent left renal features typical of xanthogranulomatous pyelonephritis, including parenchymal destruction and lipid-dense replacement.