Focal xanthogranulomatous pyelonephritis: partial nephrectomy as definitive treatment.

OBJECTIVES: We report 11 cases of focal xanthogranulomatous pyelonephritis (FXGP), a disease that is very uncommon. The aim of the present work is to assess the effectivity of conservative treatment.

MATERIAL AND METHODS: Eleven of the 82 cases of XGP (12.5%) diagnosed between 1970 and 1995 presented the focal form (FXGF). Clinical features, laboratory findings, radiological imaging studies, surgical treatment and follow-up were evaluated.

RESULTS: FXGP occurred in middle-aged women (female/male ratio 4.5:1) who had a history of calculosis, urinary infections produced by Escherichia coli and Proteus mirabilis, or urinary tract abnormalities. FXGP was unilateral in all cases. The most frequent symptom was flank pain. Some hematological and biochemical parameters were altered. Intravenous urography and sonography revealed calculosis, hydronephrosis or renal mass, but these findings are nonspecific. Only abdominal CT scan can establish the correct diagnosis. Five of these patients (45.5%) underwent partial nephrectomy at our hospital. During the follow-up, patients showed no relapse in the ipsilateral or contralateral kidney. Serum parameters were in normal range.

CONCLUSION: When FXGP is diagnosed, local excision is recommended in all cases, since relapse in the affected kidney is unusual.