# Xanthogranulomatous Pyelonephritis Presenting as Significant Hydronephrosis in an Adult Male Who Was Managed with Robotic‐Assisted Radical Nephrectomy: A Case Report and Current Literature Review

## TL;DR

A case report describes a rare kidney infection managed with robotic surgery after presenting as hydronephrosis.

## Contribution

This case highlights successful robotic-assisted radical nephrectomy for stage I XGP without prior suspicion.

## Key findings

- The patient had XGP presenting as end-stage ureteropelvic junction obstruction with normal creatinine levels.
- Robotic-assisted radical nephrectomy successfully drained over two liters of pyogenic urine during surgery.
- XGP was confirmed postoperatively despite initial lack of suspicion based on ER findings.

## Abstract

Xanthogranulomatous pyelonephritis (XGP) is an infection of the kidney that often results from a chronic obstruction, such as a kidney stone. We present a patient with a massively enlarged left renal pelvis with minimal renal parenchyma presenting as an end stage ureteropelvic junction obstruction (UPJO). The patient was afebrile during his time in the emergency room (ER). Urinalysis was significant for trace leukocyte esterase and 11–20 WBCs. His creatinine during his ER encounter was 1.02. Due to his normal creatinine, a percutaneous nephrostomy tube was not placed. Preoperatively, we did not suspect XGP or pyonephrosis given his prior ER results. Shortly after the patient′s ER presentation he was taken to surgery and final pathology revealed XGP. We were able to successfully perform a robotic‐assisted laparoscopic radical nephrectomy for stage I XGP safely, which included drainage of over two liters of pyogenic urine during the surgery.