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Xanthogranulomatous pyelonephritis in childhood: pre-operative diagnosis is possible.

OBJECTIVE
To diagnose xanthogranulomatous pyelonephritis (XGP) in childhood pre-operatively.


PATIENTS AND METHODS
Eleven cases of XGP presenting to Birmingham Children's Hospital over a 10-year-period are reported. Nine (82%) were diagnosed preoperatively on the clinical and radiological findings.


RESULTS
The characteristic clinical findings were urinary tract infection (9 cases), palpable renal mass (8 cases) and anaemia (8 cases). The most common radiological findings were enlarged kidney (9 cases), renal calculi (7 cases) and non-functioning kidney (6 cases). Renal ultrasound typically demonstrated a central echoic area (6 cases) and multiple hypoechoic areas in the parenchyma (7 cases). A computed tomography (CT) scan was performed in three cases. This showed characteristic multiple, low attenuation, unenhanced areas within the parenchyma with extension of the inflammatory process into peri-nephric fat (two cases). Ten cases (91%) were of the diffuse type. There was extension into the peri-nephric fat in eight cases (73%). Three cases (27%) were associated with congenital urological abnormalities. Nephrectomy was performed in 10 cases and a partial nephrectomy in one.


CONCLUSION
XGP is uncommon in childhood but should always be considered in the differential diagnosis of renal masses, especially in the presence of anaemia. Nephrectomy usually results in a permanent cure.