Prostatic-type polyps of the lower urinary tract: three histogenetic types?

Seventeen prostatic-type polyps of the lower urinary tract are reported. All occurred in males, and the mean ages of the patients with ureteric orifice, bladder and urethral polyps were 20.5, 60.2 and 36.6 years, respectively. The commonest presentation for the bladder and ureteric orifice polyps was haematuria, whereas that for the urethral polyps was either dysuria or haematuria. The polyps consisted of acini and papillae lined by prostatic-type epithelium, as confirmed by immunostaining for prostatic-specific antigen. Most had interspersed islands or complete covering of transitional epithelium on the surface. We believe that the histogenesis of prostatic-type polyps may differ in the different sites. For the ureteric orifice polyp, the early age of presentation and the simple occurrence of prostatic acini beneath an intact urothelium suggest a developmental abnormality. For the bladder polyp, the late onset of disease and the commonly observed transition with cystitis cystica-glandularis suggest that it may be a metaplastic variant of cystitis cystica-glandularis. On the other hand, the urethral polyp probably represents a hyperplastic lesion, since the prostatic urethra is normally lined partly by prostatic-type epithelium.