Epithelial lesions of the urinary bladder in three hundred and thirteen autopsy cases.

Urinary bladders that appeared normal macroscopically were obtained from 313 autopsy cases of both sexes and examined microscopically. Proliferative lesions such as Brunn's nests and cystitis glandularis were frequent in cases of all ages and both sexes. Metaplastic lesions such as columnar or cuboidal metaplasia and squamous metaplasia were less frequent. These two types of lesions were not related to age, but squamous metaplasia was more common in females than in males. The sites of predilection for these 4 types of lesions were the trigone and anterior wall. Hyperplasia was observed in 16.3% of the male and 10.6% of the female cases, and dysplasia in 6.8% of the male and 5.7% of the female cases. Both types of lesions were more frequent in older than younger cases. Neither type of lesions was related to chronic inflammation. One case of carcinoma in situ was found in a male. These data and mapping of the bladders indicated that none of these benign proliferative and metaplastic lesions were related with the development of dysplasia or carcinoma in situ.