Renal pelvic villous adenoma presented with mucusuria: report of a case and literature review.

Villous adenomas of the urinary tract are an uncommon condition, and appear mostly in patients where the disease occurred in the lower urinary tract. In contrast, upper urinary tract villous adenomas are a rare condition. Currently, just three cases of villous adenoma in the renal pelvis have been published. Herein, we present the fourth case of a renal pelvic villous adenoma, along with muconephrosis and mucusuria. A 73-year-old man presented with abdominal discomfort and a palpable abdominal mass. He had a history of bilateral anatrophic nephrolithotomy, 8 years and 6 years earlier. The preoperative radiographic investigation showed severe right hydronephrosis. A right nephrectomy was carried out and the intraoperative finding showed severe perinephric adhesion and a great deal of mucus in the renal pelvis. The pathological examination showed a villous adenoma and urothelial metaplasia in the kidney.