[Three cases of the nephrogenic adenoma of the bladder]

Nephrogenic adenoma is a rare, benign tumor of the urinary tract. The origin of this tumor is supposed to be a metaplastic transformation of urothelium in response to stimulation such as recurrent urinary tract infections or surgical trauma. We experienced three cases of nephrogenic adenoma originating in the bladder. The first patient was a 29-year-old man with right vesicoureteral reflux (VUR). When Teflon injection for VUR was performed, a papillary tumor was found on the right wall of the bladder. Transurethral resection of the bladder tumor (TUR-Bt) was performed. The second patient was a 72-year-old woman who was suffering from chronic cystitis. Although she was treated with antibiotics for one year, the symptoms were not improved. Cystoscopy showed multiple papillary tumors at the retrotrigonum of the bladder and TUR-Bt was performed. The third patient was a 75-year-old man who had a history of the left pelvic and bilateral ureteral tumors. Left radical nephroureterectomy and right radical ureterectomy with an ileal graft replacement was performed. Three years later, cystoscopy demonstrated a papillary tumor at the retrotrigonum, which was resected transurethrally. Our cases are the 20th to 22nd cases of the nephrogenic adenoma of the bladder reported in the Japanese literature.