[Xanthogranulomatous pyelonephritis. Our experience and review of the literature]

Ten cases of xanthogranulomatous pyelonephritis (XGP) with diagnostic and therapeutic observation are described and other experiences reported in the literature are analyzed.

The clinical, laboratory and radiological features of 10 patients who had undergone nephrectomy in our Istitute, between October 1993 and March 2000, with a postoperative pathological diagnosis of XGP have been retrospectively re-evaluated.

The most frequent symptom was flank pain. All the patients presented leucocytosis. Urine culture was positive for Proteus Mirabilis in four patients (40%) and for E. Coli in three (30%). In all the patients an ultrasound scan and urography were performed, six patients (60%) had undergone a CT scan and two of them (20%) a MRI. In six patients (60%) urinary lithiasis was associated and it was ramified in four of them (40%). The disease was always unilateral, affecting the right kidney in six cases and the left one in the other four. In three cases (30%) it presented in the focal form. The treatment was always surgical and it consisted of nephrectomy; a conservative surgical approach was used in two cases (20%). At the follow-up 4 patients (40%) showed recurrent urinary tract infections. None presented relapse.

XGP is an uncommon chronic inflammatory disease, often associated with urinary tract infections and/or urolithiasis. The clinical presentation is nonspecific so that differential diagnosis with other kidney diseases becomes difficult. A CT scan can be helpful in formulating diagnosis. The treatment is surgical and it consists of a nephrectomy, while a conservative approach can be reserved in some cases for the focal form. Cases treated with antibotics have been described.