Chronic flank pain, fever and an unusual diagnosis

Abstract

Xanthogranulomatous pyelonephritis (XGP) is a rare, serious, debilitating illness characterised by an infectious renal phlegmon. Most cases of XGP are unilateral and are often associated with urinary tract obstruction, infection, nephrolithiasis, diabetes, and/or immune compromise. This disease process ultimately results in focal or diffuse renal destruction and is characterised pathologically by lipid-laden foamy macrophages. XGP occurs in approximately 1% of all renal infections. The kidney is usually non-functional. XGP displays neoplasm like properties capable of local tissue invasion and destruction and has been referred to as a pseudotumour. Adjacent organs including the spleen, pancreas or duodenum may be involved. The gross appearance of XGP is a mass of yellow tissue with regional necrosis and haemorrhage, superficially resembling renal cell carcinoma. Renal cell carcinoma may be indistinguishable from XGP radiographically and clinically. The treatment of XGP is almost universally extirpative and can pose a formidable challenge to the surgeon.

Figure 1

Plain skiagram kidney/ureter/bladder region showing a large obstructing stone at pelvi-ureteric junction with multiple secondary stones.

Figure 2

CT urogram showing functioning right kidney, multiple left renal stones with non-excretion of contrast and per cutaneous nephrostomy tube in left kidney.

Figure 3

CECT (transverse section) showing multiple left renal stones with extensive perinephric stranding. A, aorta; D, duodenum; I, inferior vena cava; l, liver; LK, left kidney; P, pancreas; RK, right kidney.

Figure 4

CECT (transverse section) showing multiple pockets of pus collection and loss of fat planes between the kidney and surrounding structures like pancreas and spleen indicating adhesion to these structures. A, aorta; C, coeliac trunk; L, liver; LK, left kidney; P, pancreas; RK, right kidney; S, spleen.

Figure 5

CECT (sagittal section) showing multiple pockets of pus collection and loss of fat planes between the kidney and surrounding structures like pancreas and spleen. Per cutaneous nephrostomy tube is also seen. LK, left kidney; P, pancreas; PCN, per cutaneous nephrostomy; S, spleen; St, stomach.

Figure 6

CECT (coronal section) showing left kidney adherent to spleen and encasement of left renal artery by dense inflammatory reaction.

Figure 7

Left renal fossa after nephrectomy, adrenal can be seen.

Figure 8

Left kidney specimen with pus exuding.

Figure 9

Left kidney cut open along Brodel’s line revealing multiple pus pockets and stones.

Figure 10

Cut open left kidney with multiple pus pockets and stones. Also note thickening of edges indicative of extensive inflammation.