Lesions of the urinary bladder epithelium in 125 autopsy cases

One hundred and twenty five autopsy cases of macroscopically normal-appearing bladders of both sexes were examined histologically. Proliferative lesions such as Brunn's nests and cystitis glandularis, and metaplastic lesions such as columnar or cuboidal metaplasia and squamous metaplasia were commonly found and were frequently associated with lymphocytic infiltration at all ages and in both sexes. Squamous metaplasia was more common in the female than the male. Sites of predilection for these lesions were the trigone and anterior wall except for columnar or cuboidal metaplasia and dysplasia which was distributed throughout the bladder. Since these lesions were commonly found at all ages in bladders not containing neoplasia, they cannot be regarded as premalignant lesions of the bladder. Dysplasia was detected in bladders even after the 8th decade. It is not known whether these lesions are the result of chronic irritation or neoplastic stimulus.