Clinical Features of 11 Patients with Xanthogranulomatous Pyelonephritis / 대한내과학회지

ABSTRACT

BACKGROUND/AIMS: Because preoperative diagnosis of xanthogranulomatous pyelonephritis (XGP) is difficult, due to its similarities to other renal diseases, the diagnosis is made postoperatively in most cases. The purpose of this study was to describe the clinical findings in 11 patients with histologically documented XGP. METHODS: We retrospectively reviewed the characteristics, laboratory and radiological findings, preoperative diagnoses and operative methods of 11 patients with XGP, who underwent a surgical procedure or percutaneous renal biopsy. RESULTS: Among eleven patients, nine had flank pain and six had anemia. Preoperatively, three patients were diagnosed as XGP, two with renal cell carcinoma, two with renal tuberculosis, one with renal abscess, one with perirenal abscess, one with renal staghorn calculi with non-functioning kidney, and one with pyelonephrosis. On the basis of the computed tomography (CT) features, the diffuse or global forms (70.0%) were more common than the localized or focal forms (30.0%). One patient diagnosed with renal cell carcinoma preoperatively was diagnosed as XGP through an intraoperative frozen section renal tissue biopsy and underwent partial nephrectomy. One patient diagnosed as focal XGP underwent percutaneous biopsy of the renal mass, which confirmed the diagnosis. This patient received treatment with only antibiotic therapy. CONCLUSIONS: CT can be considered the preferred diagnostic tool for the evaluation of XGP; however, percutaneous renal biopsy seems to be valuable in selected cases for differential diagnosis of renal malignancy.