Clinicopathological spectrum of xanthogranulomatous pyelonephritis

Abstract

Xanthogranulomatous pyelonephritis (XGP) is an uncommon and distinct type of chronic infective pyelonephritis causing destruction of the kidney, severely affecting the renal function. The perinephric adipose tissue and peritoneum is not uncommonly involved. The study was undertaken to decipher the clinicopathologic spectrum of XGP. Forty cases of XGP were diagnosed on histopathology over a period of 13 years (2005–2017). Relevant clinical details and radiological findings were recorded from the case files. Out of a total of 40 cases, 26 were female and 14 were male with a mean age of 39.5 ± 13.6 years. Flank pain was the most common presenting symptom. All the patients had unilateral disease and underwent nephrectomy for a nonfunctional kidney. Gross examination showed enlarged kidney with replacement of cortico-medullary tissue by yellow nodular areas of fatty tissue and dilatation of the pelvicalyceal system. Thirty-six (90%) cases had nephrolithiasis. Histologically, the characteristic feature was the existence of lipid-laden foamy macrophages. Renal parenchymal involvement was diffuse in majority (31, 77.5%). Two (5.0%) of the patients had coexisting carcinoma in the same kidney. Histopathologic examination gives the definitive diagnosis of XGP which relies on the characteristic morphology. Surgical intervention in the form of nephrectomy is the treatment of choice and offers good treatment outcomes.

Concomitant xanthogranulomatous pyelonephritis with renal abscess - an unusual cause of a right flank mass

“…Causes of XGP include chronic renal obstruction, infection, abnormal lipid metabolism, lymphatic obstruction and renal ischemia. Abscess formation (as was observed in our patient), fistula formation (reno--cutaneous, reno-colonic) and profound sepsis are known complications (2).…”

Xanthogranulomatous pyelonephritis with calculus migration into the psoas abscess: an unusual complication

“…Therefore, Immunohistochemistry (IHC) study may be helpful in certain cases. 3,6 CONCLUSION XGP is an uncommon entity associated with urinary tract obstruction and infection. Also, its association with calculus migration into psoas abscess is an unusual complication.…”

“…There are three types of XGP (i) diffuse, which is the most common type; (ii) segmental; and (iii) focal, which is limited to the cortex. [5][6][7] Diffuse XGP is associated with massive renal enlargement, peri-pelvic fibrosis, hydronephrosis, lithiasis, and lobulated mass replacing the renal parenchyma. Preoperatively, it is difficult to differentiate, based on clinical and radiological features alone, XGP from other entities like tuberculosis and renal cell carcinoma (RCC).…”

Xanthogranulomatous pyelonephritis: a focus on microbiological and antibiotic resistance profiles

“…This author described forty cases of XGP and reported diffuse renal parenchymal involvement in the majority of patients (77.5%) and a high rate (90%) of nephrolithiasis. Furthermore, in their series, these authors identified 5% of coexisting renal cell carcinomas in the same kidney [ 13 ]. In our case series, we found a nephrolithiasis rate of 77.8% and only one patient presented with concomitant renal cell carcinoma (3.7%).…”