Computed Tomography Findings in Xanthogranulomatous Pyelonephritis

Abstract

Background:Xanthogranulomatous pyelonephritis (XGN) is an uncommon condition characterized by chronic suppurative renal inflammation that leads to progressive parenchymal destruction.Purpose:To review the computed tomography (CT) findings of patients diagnosed with XGN.Materials and Methods:A retrospective review of CT findings in patients with histologically proven XGN was carried out.Results:Thirteen CT examinations of 11 patients were analyzed. Renal enlargement was demonstrable on the affected side in all patients. Nine patients (82%) had multiple dilated calyces and abnormal parenchyma. Six patients (55%) had a renal pelvis or upper ureteric calculus causing obstruction. Three patients (27%) had focal fat deposits identifiable within the inflamed renal parenchyma. Two patients had renal abscesses. Ten patients (91%) had extrarenal extension of the inflammatory changes. Three patients (27%) demonstrated extensive retroperitoneal inflammation.Conclusion:Unilateral renal enlargement and inflammation were the most consistent findings of XGN on CT. Perinephric inflammation and collections or abscess should also alert the radiologist to the possibility of this diagnosis.

Pielonefritis xantogranulomatosa: Estudio retrospectivo de 8 casos

“…Los hallazgos radiológicos más destacables fueron agrandamiento renal, y litiasis coincidiendo con otras publicaciones (10)(11)(12)(13)(14)(15)(16) . La radiografía simple de ab domen permite visualizar litiasis, generalmente co raliforme y agrandamiento de la silueta renal (18)(19)(20) como ocurrió en uno de nuestros casos.…”

“…Existen diversas técnicas de imagen útiles para el diagnóstico inicial, destacando la radiografía abdominal, urografía intravenosa, pielografía retrógrada y angiografía, aunque en la práctica se utiliza la ecografía y la TC por tener mayor sensibilidad y especificidad (10)(11)(12)(13)(14)(15)(16)(17) .…”

Fever of unknown origin (FUO) and a renal mass: Renal cell carcinoma, renal tuberculosis, renal malakoplakia, or xanthogranulomatous pyelonephritis?

“…Malakoplakia may rarely present with an FUO. 21,[23][24][25][26][27][28][29][30][31][32][33] Fevers of unknown origin attributable to renal cell carcinoma may not present with a flank mass or hematuria. [4][5][6] In our patient with an FUO, the nephrectomy specimen demonstrated pathology compatible with xanthogranulomatous pyelonephritis with typical lipid-laden macrophages.…”

“…Findings of CT include unilateral renal enlargement. [23][24][25][26][27][28][29][30][31][32][33] Renal cell carcinoma is a great imitator, and has been termed "the internist's tumor" because of its myriad clinical manifestations. It may present clinically and radiographically as xanthogranulomatous pyelonephritis, and therefore should always be included in the differential diagnosis of a renal mass.…”

Xanthogranulomatous pyelonephritis: the case of a perplexing kidney

“…CT is the mainstay for diagnosis. Typically associated with a staghorn calculus, the kidney shows loss of the normal cortex with multiple low attenuation areas that represent areas of renal tissue replaced with lipid-laden macrophages 2. Percutaneous drainage and adjunctive antibiotic therapy prior to nephrectomy are recommended to avoid complications 3.…”