Clinical Characteristics of Xanthogranulomatous Pyelonephritis / 대한비뇨기과학회지

ABSTRACT

PURPOSE: In most cases, xanthogranulomatous pyelonephritis (XGP) is diffusely or focally enlarged, mimicking a neoplastic process. The purpose of this study was to improve the preoperative diagnosis of this disease. MATERIALS AND METHODS: The clinical characteristics, laboratory and radiological findings, preoperative diagnoses and operative methods of 13 patients with XGP, who underwent an operation between 1979 and 2004, were retrospectively reviewed. All patients had undergone intravenous pyelography(IVP) and ultrasonography. Their mean age was 51+/-3.3 years (range 30 to 71), with a male to female ratio of 4 to 9. RESULTS: All 13 patients had flank pain, 8(61.5%) had a urinary tract infection and 9(69.2%) with benign renal disease preoperatively underwent a simple nephrectomy. Four patients preoperatively diagnosed with a renal cell carcinoma(RCC) underwent a radical nephrectomy. 3 patients had extended to the psoas muscle. On the basis of the ultrasonographic features (1) 6(46.1%) were diffuse hydronephrotic; (2) 4(30.8%) were diffuse parenchymal; (3) 2(15.4%) were diffuse contracted, and (4) 1(7.7%) was segmental or focal. On the basis of the computed tomography(CT) features, the diffuse or global forms(88.9%) were more common than the localized or focal forms(11.1%). Diffuse XGP may be staged as follows Stage I(25%), involvement is limited to the kidney; Stage II(50%), involvement extends to the perirenal fat within Gerota's fascia; Stage II(25%), involvement extends beyond the Gerota's fascia into another organ. CONCLUSIONS: Preoperative diagnosis of XGP will be raised through a better understanding of the characteristics and radiological findings of this disease.