Widespread mucous metaplasia of the urinary bladder with nephrogenic adenoma.

We describe widespread metaplastic changes observed in nonexstrophic urinary bladder mucosa in a 32-year-old man. Extensive areas of the luminal surface were covered by two types of metaplastic epithelium. One type was bilayered while the other was single layered with columnar cells of varying electron density as well as mucus-secreting cells. An area of adenomatoid metaplasia was also observed.