Xanthogranulomatous Pyelonephritis: Intrahepatic and Intrathoracic Extension

Area of Science:

• Nephrology
• Pathology
• Radiology

Background:

• Xanthogranulomatous pyelonephritis (XGP) is a rare, chronic, destructive inflammatory kidney disease.
• It is often associated with obstructing kidney stones and recurrent urinary tract infections (UTIs).
• While invasive XGP is documented, extra-abdominal spread is exceptionally uncommon.

Observation:

• A 32-year-old female presented with persistent cough, fever, and malaise.
• Clinical examination revealed an enlarged right kidney with decreased breath sounds on the right.
• Radiological imaging showed a large right kidney invading the liver and right pleural space.

Findings:

• Intraoperative findings confirmed the right kidney invading the liver and right pleural cavity via a diaphragmatic defect.
• Histopathology of the kidney demonstrated foamy histiocytes, characteristic of XGP.
• The case presented an unprecedented invasion into extra-abdominal structures.

Implications:

• This case expands the known spectrum of xanthogranulomatous pyelonephritis presentation.
• It underscores the importance of considering rare differentials in complex cases with atypical radiological findings.
• Further research may be warranted to understand the mechanisms and risk factors for such extensive invasion.