Xanthogranulomatous Pyelonephritis: Experience in 36 Cases

Abstract

A retrospective study of 36 patients with xanthogranulomatous pyelonephritis who underwent nephrectomy at our hospital was performed. The disease occurred most frequently in middle-aged women with a history of recurrent urinary tract disorder. There were 2 cases of focal xanthogranulomatous pyelonephritis, 2 associated with emphysematous pyelonephritis, 2 that manifested as fistula formation between the colon or skin, and 1 with deep sinus formation into the hip joint that presented as septic arthritis. Flank pain and fever were the most frequent complaints. Escherichia coli (67%) and Proteus mirabilis (26%) were the most common organisms isolated from the voided urine, kidney and blood stream. Cephalothin plus gentamicin or tobramycin were the drugs of choice before surgical intervention.

Granulomatous pyelitis associated with urinary obstruction: a comprehensive clinicopathologic study

“…Xanthogranulomatous pyelonephritis and granulomatous pyelitis share a similar clinical background, involvement of the pyelocalyceal system, and granulomatous inflammation; however, several features characteristic for xanthogranulomatous pyelonephritis are not seen in granulomatous pyelitis, including acccumulation of foamy macrophages, inflammatory changes affecting not only the pyelocalyceal system, but also renal parenchyma, and perirenal and peripelvic soft tissue. 16,17 Indeed, one current case (Case 4) was initially misdiagnosed as xanthogranulomatous pyelonephritis. Michealis-Guttman bodies, a pathognomonic feature of renal malakoplakia, are never seen in any other condition including granulomatous pyelitis; furthermore, malakoplakia usually involves the renal parenchyma rather than the renal pelvis.…”

“…Michealis-Guttman bodies, a pathognomonic feature of renal malakoplakia, are never seen in any other condition including granulomatous pyelitis; furthermore, malakoplakia usually involves the renal parenchyma rather than the renal pelvis. 16,18,19 Necrotizing granulomatous inflammation and pyelocalyceal dilatation are seen in both renal tuberculosis and granulomatous pyelitis; however, renal tuberculosis is characterized by granulomatous inflammation involving predominantly the renal parenchyma, and much less frequently affecting the pyelocalyceal system; other characteristic features of renal tuberculosis including simultaneous active infection of lung or other genitourinary organs, frequent bilateral renal involvement, and positive acid fast bacilli by special stains or culture should be definitive. 16 Fungal infection of the kidney is almost always limited to immunosuppressed patients, with renal involvement reminiscent of acute pyelonephritis rather than granulomatous inflammation; it is associated with abundant organisms detected by special stains, but prominant pyelocalyceal involvement or urinary tract obstruction is not features of renal fungal infection.…”

“…16,18,19 Necrotizing granulomatous inflammation and pyelocalyceal dilatation are seen in both renal tuberculosis and granulomatous pyelitis; however, renal tuberculosis is characterized by granulomatous inflammation involving predominantly the renal parenchyma, and much less frequently affecting the pyelocalyceal system; other characteristic features of renal tuberculosis including simultaneous active infection of lung or other genitourinary organs, frequent bilateral renal involvement, and positive acid fast bacilli by special stains or culture should be definitive. 16 Fungal infection of the kidney is almost always limited to immunosuppressed patients, with renal involvement reminiscent of acute pyelonephritis rather than granulomatous inflammation; it is associated with abundant organisms detected by special stains, but prominant pyelocalyceal involvement or urinary tract obstruction is not features of renal fungal infection. 16 Patients with granulomatous tubulointerstitial nephritis are usually diagnosed in the context of a medical condition requiring renal biopsy, which show granulomatous inflammation in the renal parenchyma rather than involvement of the pyelocalyceal system.…”

“…16 Fungal infection of the kidney is almost always limited to immunosuppressed patients, with renal involvement reminiscent of acute pyelonephritis rather than granulomatous inflammation; it is associated with abundant organisms detected by special stains, but prominant pyelocalyceal involvement or urinary tract obstruction is not features of renal fungal infection. 16 Patients with granulomatous tubulointerstitial nephritis are usually diagnosed in the context of a medical condition requiring renal biopsy, which show granulomatous inflammation in the renal parenchyma rather than involvement of the pyelocalyceal system. 20,21 Encrusted pyelitis is rare condition characterized by marked tissue deposition of calcium-containing material, associated with severe necrotic debris and predominantly acute inflammation.…”

Giant Size Xanthogranulomatous Pyelonephritis: A Case Report

“…There is diffuse obstructive infection, accumulation of lipidladen macrophages associated with impairment of local immunity and granulomatous infiltration (4,5). Such cases may be confused with neoplastic or inflammatory renal parenchymal diseases.…”