Epithelial Metaplasia
- Squamous metaplasia — often a knobby appearance covered by white, flaky, easily disrupted material on the trigone. Present in ~40% of women and 5% of men, usually related to infection, trauma, or surgery; a normal finding in premenopausal females.
- Glandular metaplasia — clumps of raised red, inflammatory-appearing areas, often confused for cancer.
No treatment is needed for either.
Leukoplakia
Similar to squamous metaplasia, with the addition of keratin deposition appearing as a white, flaky substance floating in the bladder. No treatment is needed.
Urothelial Papilloma
Composed of delicate stalks lined by normal-appearing urothelium. May recur, but does not progress or invade.
Inverted Papilloma
Associated with chronic inflammation or bladder outlet obstruction; can occur throughout the bladder but is most common on the trigone. 1% recurrence, but does not progress or invade. Treated by transurethral resection.
Nephrogenic Adenoma
Rare; caused by chronic irritation of the urothelium and also associated with trauma, previous surgery, renal transplantation, intravesical chemotherapy, stones, catheters, and infection.
Cystitis Cystica and Glandularis
A common finding in normal bladders, usually associated with inflammation or chronic obstruction; cystitis glandularis may be associated with pelvic lipomatosis. Regular endoscopic evaluation is recommended, as there are a few case reports of transformation into adenocarcinoma.
Leiomyoma
Occurs most commonly in women of childbearing age; surgical resection is required if large or painful.
Endometriosis
Can be treated with hormones, TUR, or partial cystectomy.
Self-Test
1. List the benign tumours of the bladder. Epithelial metaplasia, leukoplakia, urothelial papilloma, inverted papilloma, nephrogenic adenoma, cystitis cystica/glandularis, leiomyoma, and endometriosis.