Nephrogenic metaplasia (adenomatoid tumors) of bladder.

Two cases of rare nephrogenic metaplasia of the bladder (adenomatoid bladder tumor) support the theory that these tumors originate as an atypical metaplastic response of urothelium to chronic infection or irritation. That these may also represent mesonephric or mesothelial choristomas is considered. Although benign, they may recur. Therapy should consist of antibiotics and transurethral resection or fulguration.