Benign Tumors of the Bladder

Epithelial Metaplasia Squamous Metaplasia Keratinizing squamous metaplasia •Associated with long-standing mucosal irritation, such as prolonged catheterization, lithiasis, chronically infected bladder, diverticula or schistosomiasis. •More common in patients with spinal injury or paraplegia. •Can be visualized as gray to white patches or plaques. •Histology: hyperkeratotic squamous epithelium •Can be associated with concurrent or subsequent carcinomas with squamous differentiation, and suggested as precursor lesion for squamous cell carcinoma.  ? !!

Benign Tumors of the Bladder Epithelial Metaplasia Leukoplakia Inverted Papilloma Papilloma Nephrogenic Adenoma Cystitis Cystica and Glandularis Leiomyoma

Leukoplakia = Keratinizing Squamous Metaplasia Leukoplakia of the bladder - Similar to squamous metaplasia with the addition of keratin deposition that appears as a white flaky substance floating in the bladder (Staack et al, 2006). - Leukoplakia occurs in other organs that are covered by squamous epithelium and is often premalignant However, cytogenetic studies on bladder leukoplakia are consistent with a benign lesion, and no treatment is necessary (Staack et al, 2006).

Leukoplakia = Keratinizing Squamous Metaplasia Leukoplakia is a clinical term indicating "white plaque." Leukoplakia is known to occur in the mucous membranes of the body, including those of the urinary tract, rectum, vagina, uterus, vulva, paranasal sinuses, gallbladder, esophagus, eardrums, and pharynx. Currently, the clinical term "leukoplakia" is thought to be synonymous with the histopathologic diagnosis of keratinizing squamous metaplasia.

Leukoplakia = Keratinizing Squamous Metaplasia Metaplastic changes of the urothelium are associated with chronic inflammation, diverticuli, or stones and should not be confused with squamatization of the trigone (nonkeratinizing glycogenated squamous epithelium), which is a common occurrence in women during estrogen production. Hormone-associated squamatization of the trigone demonstrates no keratinization, intercellular bridges, or cellular atypia and is considered a normal anatomic variant.