"stage I: the disease is confined to the renal parenchyma only"
"stage II: involves renal parenchyma as well as an extension to perirenal/perinephric fat"
"stage III: the disease extends into the perirenal and pararenal spaces or diffuse retroperitoneum"
Expected headings
"Associations"
"Urography (CT/conventional)"
"Xanthogranulomatous pyelonephritis is seen essentially in all age groups, but most frequently presents in middle-aged to elderly patients 1,8. There is a 2:1 female predilection 8."
"There is also a more focal form of xanthogranulomatous pyelonephritis, where a small low attenuation mass with an associated calculus is seen adjacent to a calyx or in one pole of a kidney."
"Xanthogranulomatous pyelonephritis is, as the name suggests, a chronic granulomatous process believed to result from subacute/chronic infection inciting a chronic but incomplete immune reaction 1,4. Various bacteria are isolated; however, the most commonly isolated species are Escherichia coli and Proteus mirabilis 1,4,8."
"Plain radiograph findings are difficult to distinguish from a routine staghorn calculus, although fragmentation and enlargement of the renal outline may be seen. A calculus is not always present; in such cases, it is not possible to make a plain film diagnosis."
"Despite often absent urinary tract symptoms, pyuria and positive urinary cultures are present in the majority of cases (95% and 60%, respectively) 2."
"If xanthogranulomatous pyelonephritis becomes established, conservative treatment (e.g. antibiotics) or minimally invasive intervention (e.g. ureteric stenting, percutaneous nephrostomy, percutaneous abscess drainage) has limited success, and nephrectomy is usually required for definitive treatment 4,5,8."