Case Report on Bilateral Xanthogranulomatous Pyelonephritis Secondary to Obstructive Uropathy and Genitourinary Tuberculosis in A 38-Year-Old Male

Abstract

Xanthogranulomatous pyelonephritis (XGP) is a rare renal infection linked to obstructive uropathy. A 38-year-old male with genitourinary tuberculosis presented with fever and flank pain. MDCT confirmed bilateral XGP. He was successfully treated with antibiotics, leading to improved renal function.

Keywords

Introduction

An uncommon renal condition known as xanthogranulomatous pyelonephritis (XPGN) affects 0.6 to 1% of all instances of renal infections.¹ The major cause of it is considered to be obstructive uropathy. This syndrome is characterised by lipid-laden macrophages called xanthoma cells invading the renal parenchyma.² We report the case of  38-year-old male with genitourinary TB and obstructive uropathy presented with complaints of fever, vomiting, and right flank pain. MDCT of KUB confirmed bilateral  XGP, revealing the hallmark "bear's paw sign."

MATERIALS AND METHODS

Study Design: Single-patient case report

Diagnostic Tool Used:  ultrasonography

Data Sources: Clinical presentation, physical examination, imaging findings

Ethical Considerations: Patient identity not disclosed

CASE PRESENTATION

A 38-year-old male patient, a known case of genitourinary tuberculosis  and obstructive uropathy who   also underwent urethrotomy for urethral stricture , presented with fever and abdominal pain that was sudden in onset, rapidly progressive, and localized to the right lumbar and flank region for three days.

On physical examination, his blood pressure and pulse rate were  130/70 mmHg, and 82 beats per minute, per-abdomen examination revealed a soft, non-distended abdomen with tenderness in the right lumbar and flank regions.

Laboratory investigations showed haemoglobin levels of 9 g/dL and an RBC count of 3.6 million cells/mm³, indicating anemia. Serum creatinine was elevated at 8.14 mg/dL, and blood urea was 116.4 mg/dL, suggesting significant renal dysfunction. 

MDCT of the kidneys, ureters, and bladder (KUB) revealed an enlarged right kidney (14.2 × 8.0 cm) with gross hydroureteronephrosis and thinning of the renal parenchyma. The dilated pelvicalyceal system showed low-attenuation, multiple rounded dilated calyces, and thin renal parenchyma, presenting a "bear's paw sign." The right ureter was dilated and tortuous with minimal peri-ureteric fat stranding. 

The left kidney was mildly enlarged (13.0 × 6.7 cm) with gross hydronephrosis, thinning of the parenchyma, and tiny hyperdense foci (HU ~148) in the subcortical region of the lower pole, likely representing renal calculi. Mild perinephric and peri-ureteric fat stranding with thickening of Gerota's, Zuckerkandl's, and lateral conal fascia were noted. The gallbladder was well distended with tiny calculi, the largest measuring 3.5 mm. Enlarged lymph nodes were observed in the pre/para-aortic and mesenteric regions, the largest having a short-axis diameter of 14 mm. 

These MDCT findings of the KUB suggested features consistent with bilateral xanthogranulomatous pyelonephritis.

The patient received treatment with a beta-lactamase inhibitor (sulbactam 500 mg )and a third-generation cephalosporin (ceftriaxone 1000 mg)[1-0-1] .The creatinine levels were lowered to 3.2 mg/dL and further he was managed conservatively.

DISCUSSION

Bilateral XGP is a rare, chronic granulomatous renal disease caused by long-term urinary obstruction and infection. While nephrectomy is the preferred treatment for advanced cases, antibiotic therapy is effective if diagnosis is confirmed through biopsy or clinical and cytologic findings. A similar case in a 47-year-old female presented only with malaise. Rossi, Vandenris, and Smith reported bilateral XGP cases without neurogenic vesical dysfunction.^3,4 This case is unique due to coexisting genitourinary tuberculosis, a rare condition. Severe XGP often requires nephrectomy, as antibiotics are ineffective. GUTB causes fibrosis, strictures, and obstruction, leading to renal dysfunction. Early diagnosis and intervention are essential to prevent irreversible kidney damage.^5,6

RESULT

In conclusion, this case report highlights a rare instance of bilateral xanthogranulomatous pyelonephritis (XGP) in a patient with genitourinary tuberculosis and obstructive uropathy. Early diagnosis with MDCT imaging and rapid medical care with antibiotics resulted in dramatically improved kidney function. This instance emphasises the significance of early management in averting serious renal consequences in XGP.

REFERENCES

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6. Perez LM, Thrasher JB, Anderson EE. Successful management of bilateral xanthogranulomatous pyelonephritis by bilateral partial nephrectomy. J Urol 1993;149:100–2.