[Two cases of vesical nephrogenic adenoma].

Case 1: A 52-year-old man receiving regular treatment for quadriplegia due to Friedreich disease visited our hospital with the chief complaint of macroscopic hematuria. He had undergone cystostomy 12 years ago due to neurogenic bladder. The computed tomography and cystoscopic examination revealed a bladder tumor with a few bladder stones. Transurethral resection of bladder tumor (TUR-Bt) was performed after bladder stone removal in May 2000. The pathological diagnosis showed nephrogenic adenoma. Case 2: A 54-year-old man had been treated with bladder tumor by TUR-Bt in Nov. 1995. The pathological diagnosis showed transitional cell carcinoma, G3, pT2 and intravesical instillation therapy using THP was performed. The bladder tumor had recurred twice and the instillation therapy had been exchanged to BCG since Nov. 1997. A small bladder tumor was observed in Jan. 2001, and from the biopsy specimen it was diagnosed as nephrogenic adenoma. Forty-six cases of urothelial nephrogenic adenoma including our cases have been reported in Japan. Chronic stimulation such as bladder stone and infection is thought to induce nephrogenic adenoma. BCG instillation therapy is believed to be an initiation factors for nephrogenic adenoma.