Xanthogranulomatous pyelonephritis (XGP) is a very rare form of kidney disease characterized by destruction of renal parenchyma, its fibrosis, and its replacement by lipid-laden macrophages. 11 Chuang CK, Lai MK, Chang PL, et al. Xanthogranulomatous pyelonephritis: experience in 36 cases.J Urol. 1992;147:333-336.,22 Parsons MA, Harris SC, Longstaff AJ, Grainger RG. Xanthogranulomatous pyelonephritis: a pathological, clinical, and etiological analysis of 87cases. Diagn Histopathol.1983; 6:203-219..
We describe a case of a 46-year-old woman with bilateral staghorn stones and end-stage renal disease (ESRD) under renal replacement therapy by hemodialysis. An abdominal CT scan suggested bilateral XGP (Figure 1) and she was submitted to bilateral nephrectomy. Histopathological analysis confirmed the diagnosis.
Complications in XGP can occur, such as cortical atrophy, abscesses, and kidney loss. The treatment of choice is total nephrectomy, and tumors and granulomatous diseases should be included in the differential diagnosis33 Kuo C, Wu C, Huang C, et al. Xanthogranulomatous pyelonephritis: critical analysis of 30 patients. Int Urol Nephrol. 2011; 43:15-22. doi:10.1007/s11255- 010-9778-8.
https://doi.org/10.1007/s11255-...
4 Ramboer K, Oyen R, Verellen S, et al.Focal Xanthogranulomatous pyelonephritis mimicking a renal tumor: CT- and MR findings and evolution under therapy. Nephrol Dial Transp. 1997; 12: 1028-1030.-55 Guzzo TJ, Bivalacqua TJ, Pierorazio PM, et al. Xanthogranulomatous pyelonephritis: presentation and treatment in the laparoscopy era. BJU Int. 2009; 104: 1265..
CT scan showing the “bear paw sign” in both kidneys (a) and staghorn stones with bilateral hydronephrosis (b). Gross pathological examination showing bilateral cystic formations, abscesses, and fibrosis with architectural distortion of the renal parenchyma (c). Optical microscopy showing numerous macrophages, some with xanthomized aspect (d) and renal parenchyma with focus of histiocytic reaction and areas of necrosis (e).
References
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1Chuang CK, Lai MK, Chang PL, et al. Xanthogranulomatous pyelonephritis: experience in 36 cases.J Urol. 1992;147:333-336.
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2Parsons MA, Harris SC, Longstaff AJ, Grainger RG. Xanthogranulomatous pyelonephritis: a pathological, clinical, and etiological analysis of 87cases. Diagn Histopathol.1983; 6:203-219.
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3Kuo C, Wu C, Huang C, et al. Xanthogranulomatous pyelonephritis: critical analysis of 30 patients. Int Urol Nephrol. 2011; 43:15-22. doi:10.1007/s11255- 010-9778-8.
» https://doi.org/10.1007/s11255- -
4Ramboer K, Oyen R, Verellen S, et al.Focal Xanthogranulomatous pyelonephritis mimicking a renal tumor: CT- and MR findings and evolution under therapy. Nephrol Dial Transp. 1997; 12: 1028-1030.
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5Guzzo TJ, Bivalacqua TJ, Pierorazio PM, et al. Xanthogranulomatous pyelonephritis: presentation and treatment in the laparoscopy era. BJU Int. 2009; 104: 1265.
Publication Dates
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Publication in this collection
28 May 2021 -
Date of issue
Jul-Sep 2021
History
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Received
12 Nov 2020 -
Accepted
18 Apr 2021