[Case of inflammatory pseudotumor occurring in the renal pelvis]

Inflammatory pseudotumor most commonly involves the lung. However, inflammatory pseudotumor has been reported in various sites in the abdomen, including the kidneys, retroperitoneum and urinary tract. We present a rare case of pathologically proven inflammatory pseudotumor in the renal pelvis. A 45-year-old woman was referred to our hospital with gross hematuria. Computed tomography demonstrated a mass around the right renal pelvocalyceal system suggestive of cystic renal cell carcinoma. Retrogradepyelography was done. Pelvic urine cytology was class III. The possibility of urothelial carcinoma could not be denied. Retroperitoneoscopic nephroureterectomy with open bladder cuff excision was performed. The histological examination revealed an inflammatory pseudotumor. She showed no evidence of disease 44 months after the operation.