[Xanthogranulomatous pyelonephritis]

Based on the evidence obtained on 28 cases of xanthogranulomatous pyelonephritis (XP), the authors suggest to distinguish two XP clinical forms: obstructive and nonobstructive. The former may occur in noticeable destruction of renal tissue and urine retention secondary, most frequently, to long-standing nephrolithiasis. The latter simulates by symptoms and examination results renal carcinoma. In suspicion of nonobstructive XP, the surgeon should consider fast-made intraoperative biopsy to decide on feasibility of sparing intervention.