Adenomatous metaplasia (nephrogenic adenoma) of urothelium. An analysis of 70 cases.

A retrospective analysis of 70 cases of adenomatous metaplasia seen in the St Peter's Hospitals over a 15-year period has been carried out. The lesions occurred at all ages (7-81 years) and in both sexes (51 males, 19 females) and were found throughout the urinary tract from pelvis to urethra. In the pelvis and ureter the finding was usually an incidental one in association with stones or chronic inflammation; ulceration was a frequent accompaniment. Most vesical and urethral lesions followed a surgical procedure months or years previously, the patients re-presenting with haematuria or irritative bladder symptoms. The endoscopic appearances varied but there was often a striking correlation between the location of the lesions and the site of previous surgery. The association of adenomatous metaplasia with ulceration and previous surgery leads us to suggest that it is merely an unusual response to wound healing and attempts to treat it by diathermy resection are, therefore, likely to meet with limited success. Cystoscopic follow-up of persistent lesions gives no reason to suppose they are pre-malignant.