Nephrogenic adenoma in patients with transitional cell carcinoma of the bladder receiving intravesical thiotepa.

Nephrogenic adenoma is a rare, benign lesion of the urothelium that generally occurs after open surgery or other bladder trauma. We present 2 recently treated patients with nephrogenic adenomas, both of whom had been treated previously with transurethral resection and intravesical thiotepa for histologically proved transitional cell carcinoma of the bladder. The occurrence of nephrogenic adenoma after transurethral resection alone is extremely rare and suggests a possible adjuvant role of the intravesical thiotepa. With the increasing use of such local chemotherapeutic agents, the incidence of nephrogenic adenoma in such patients may be increasing.