Saudi Journal of Kidney Diseases and Transplantation

: 2010  |  Volume : 21  |  Issue : 3  |  Page : 515--517

Xanthogranulomatous pyelonephritis in a Horse-Shoe kidney

Ritesh Mongha1, Arindam Dutta1, Mukesh Vijay1, Uttara Chatterjee2, Sudip C Chakraborty1,  
1 Department of Urology, Institute of Post-Graduate Medical Education and Research (IPGMER) & SSKM Hospital, Kolkata, India
2 Department of Pathology, Institute of Post-Graduate Medical Education and Research (IPGMER) & SSKM Hospital, Kolkata, India

Correspondence Address:
Sudip C Chakraborty
Department of Urology, IPGMER & SSKM Hospital, Kolkata


Xanthogranulomatous pyelonephritis (XGPN) represents an unusual suppurative gra要ulomatous reaction to chronic infection, often in the presence of chronic obstruction from a calculus. We present a case of XGPN in a horse shoe kidney in an adult. Hemi-nephrectomy of the involved side was followed by clinical improvement. The case highlights the importance of early hemi-nephrectomy in XPGN with horse shoe kidney.

How to cite this article:
Mongha R, Dutta A, Vijay M, Chatterjee U, Chakraborty SC. Xanthogranulomatous pyelonephritis in a Horse-Shoe kidney.Saudi J Kidney Dis Transpl 2010;21:515-517

How to cite this URL:
Mongha R, Dutta A, Vijay M, Chatterjee U, Chakraborty SC. Xanthogranulomatous pyelonephritis in a Horse-Shoe kidney. Saudi J Kidney Dis Transpl [serial online] 2010 [cited 2020 Jul 13 ];21:515-517
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Full Text


Xanthogranulomatous pyelonephritis (XGPN) is a chronic renal infection typically resulting in diffuse renal destruction. The disease is asso苞iated with obstructive uropathy secondary to nephrolithiasis resulting in a nonfunctioning, enlarged kidney in most cases. The pathologic process is usually unilateral, though cases of bilateral disease have been reported. [1] Literature review revealed only one case of XGPN in a horse shoe kidney, reported in a child. No such case has been earlier reported in an adult. [2] We present a case of Xanthogranulomatous pyelo要ephritis in a horse shoe kidney in an adult. Radiological and histopathological features of the disease are also discussed.

 Case Report

A 62-year-old male was admitted with dull aching and non-radiating pain in the left lumbar region and low grade fever of ten days duration. The patient had no past history of renal disease orhypertension. Physical examination showed mild pallor, tachycardia, and temperature of 101΀F. Abdominal examination showed a soft and lax abdomen with no lump or organome茆aly. Laboratory tests revealed hemoglobin of 9.9 gm/dL, leukocyte count of 9000/mm 3 with polymorphs 74%, urea 84 mg%, serum creati要ine 2.0 mg%, Na + 128 Meq /L and serum K + 4.6 Meq/L. Urinalysis revealed alkaline pH and pus cells 22-24 per high power field. Urine culture grew E. Coli sensitive to ceftriaxone and oflo軍acin. Patient's abdominal ultrasound showed left sided nephrolithiasis and hydronephrosis with complex cystic SOL in the upper pole of left kidney with ectopic right kidney. Computed to衫ographic (CT) scan revealed horseshoe kidney, hydronephrotic left kidney with multiple cal苞uli; renal parenchyma on left side was replaced by low attenuation masses representing dilated calyces and abscess filled cavities suggestive of Xanthogranulomatous pyelonephritis [Figure 1]. DMSA scan showed enlarged left Kidney ex負ending downward towards ectopically placed right kidney. Outline of the left side was smooth and showed only 9.45% of total relative uptake. GFR of left kidney was 4 mL/min and of the right side 14 mL/min on DTPA scan.

Surgical exploration revealed horse-shoe kid要ey with left kidney side having dense peri要ephric inflammatory extension into the retro計eritoneum upto the midline. Left Hemi-neph訃ectomy was done with removal of all inflamed and infected perinephric tissues. Specimen was full of purulent material and contained multiple calculi within the pelvi-calyceal system. Post operative course was uneventful and serum crea負inine came down to 1.2 mg% on 7 th post-ope訃ative day and the patient was discharged on oral antibiotics for 2 weeks.

Biopsy of the resected specimen showed sheets of inflammatory cells, lymphoid follicles, atro計hic glomeruli and tubules on low power (H & E Χ 40) [Figure 2]. High power view (H & E Χ 400), revealed sheets of foamy macrophages (Xanthoma cells) confirming XGPN [Figure 3]. At 16 weeks follow up patient was asympto衫atic and the serum creatinine level further de苞lined to1.0 mg%. DTPA scan showed im計rovement in GFR of the right kidney to 29.03 mL/min with all phases of renogram within normal limits.


XGPN represents an unusual suppurative gra要ulomatous reaction to chronic infection, often in the presence of chronic obstruction from a calculus. XGPN occurs in approximately 1% of all renal infections. XGPN is four times more common in women than men and is usually no負ed in the fifth and sixth decades of life. XGPN displays neoplasm like properties capable of local tissue invasion and destruction and has been referred to as a pseudo tumor. [3] XGPN has been described in three stages, as follows:

kidney alone,kidney and perinephric fat, andkidney, perinephric fat and retroperitoneum extension. [1]

The gross appearance of XGPN is a mass of yellow tissue with regional necrosis and hemo訃rhage, superficially resembling renal cell carci要oma. The microscopic features of XGPN are the presence of foamy lipid-containing macro計hages (xanthoma cells), diffuse infiltration with plasma cells, and histiocytes. [4] Focal abscesses may be observed. Complete Blood Count may reveal leukocytosis and anemia. Serum chemis負ries determine the presence of any baseline electrolyte abnormalities, though none are pa負hognomonic of XGPN. Contrast enhanced CT is a reliable method to diagnose XGPN and to establish the presence and extent of extrarenal involvement. The CT findings of XGPN are calculi (75-86%), increase in renal volume (5560%), hydronephrosis (80%), hypodense areas with density measurements from 15 to 25 HU representing focal areas of parenchymal des負ruction filled with pus and/or debris, rim en虐ancement of these low density areas and ex負rarenal involvement, which is seen in 15-20% of cases. [5],[6] This disease process shares many characteristics with a true neoplasm in terms of its imaging appearance and ability to involve adjacent structures or organs. The present in苞reasingly sensitive radiological investigations, especially the CT-scan, in combination with clinical suspicion, have made the preoperative diagnosis of XGPN possible. [7] XGPN is noto訃ious for fistulization; pyelo-or uretero-cutaneous fistulae are well described, and occasionally may involve the bowel resulting in pyeloenteric fis負ula. The overall prognosis for XGPN is good. Death from this entity is exceedingly rare, though morbidity is substantial. [8]

In patients of XGPN in a fused kidney, we believe that local extension of disease and in苯lammatory mediators secreted from the Xan負hogranulomatous kidney may be the possible causes of deterioration of function on the other side too. Nephrectomy is the standard treatment for XGPN and in patients with fused kidney should be done early to limit the extension of disease to the better kidney and for its reco赳erability. The function in the other half of horse-shoe kidney improved after hemi-neph訃ectomy in our case. Radionuclide studies are extremely useful in assessing differential renal function in patients of XGPN as well as in follow up of these patients. [9] Patients should be on antibiotics for about two weeks postope訃atively for control of infection and a close long term follow up is recommended.


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