Inverted Papilloma of the Bladder

 

PPT : Inverted Papilloma Bladder.ppt

Inverted Papilloma

• Rare, ~1% of urothelial neoplasms seen over a wide age range
• Cystoscopy shows small (<3 cm) solitary sessile lesion or may have a short stalk.


• Histology:
  ◦Urothelium invaginates into lamina propria (inverted).
  ◦Characterized by cords or trabeculae with peripheral palisading of basal cells and central streaming cells.
  ◦Cords should be thin (a must, to distinguish from higher grade inverted urothelial neoplasms).
  ◦Bland cytology, but may have scattered degenerative atypia.

• Benign proliferative lesion (associated with chronic inflammation or bladder outlet obstruction)
• Can be located throughout the bladder but most commonly on the trigone, comprising less than 1% of all bladder tumors
• Inverted growth pattern (anastomosing islands of histologically and cytologically normal urothelial cells invaginating from the surface urothelium into the lamina propria but not into the muscularis propria)
• Behave in a benign fashion with only a 1% incidence of tumor recurrence. (Negligible recurrence rate (<1%))
• Occasionally, present with coexistent urothelial cancer elsewhere in the urinary system, occurring more commonly in the upper tract than the bladder
• The use of fluorescent in-situ hybridization (FISH) to evaluate chromosomal changes can distinguish between an inverted papilloma and a urothelial cancer with an inverted growth pattern (Jones et al, 2007).
• Transurethral resection is the treatment of choice.



Referrence

1. Campbell Urology
  Chapter 80 : Urothelial Tumors of the Bladder

 

 

PPT : Inverted Papilloma Bladder.ppt

Leukoplakia of the Bladder (Vesical Leukoplakia) PPT

Leukoplakia of the Bladder (Vesical Leukoplakia)

  Leukoplakia is a clinical term indicating "white plaque."
  And also, leukoplakia is the clinical manifestation of histologically described keratinizing squamous metaplasia.

  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.

  It is distinctly different from estrogen-associated squamous metaplasia of the female trigone. (Nonkeratinizing 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.

- 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).

 

Referrence 

1. Campbell Urology
   Chapter 80 : Urothelial Tumors of the Bladder

2. Staack A, Schlechte H, Sachs M, et al. Clinical value of vesical leukoplakia and evaluation of the neoplastic risk by mutation analyses of the tumor suppressor gene TP53. Int J Urol 2006;13(8):1092–7.

PPT : Vesical Leukoplakia.ppt

Epithelial Metaplasia of the Bladder

Epithelial Metaplasia

Metaplasia (Greek: "change in form")

- Reversible replacement of one differentiated cell type with another mature differentiated cell type

- The change from one type of cell to another may generally be a part of normal maturation process or caused by some sort of abnormal stimulus.

- In simplistic terms, it is as if the original cells are not robust enough to withstand the new environment, and so they change into another type more suited to the new environment. If the stimulus that caused metaplasia is removed or ceases, tissues return to their normal pattern of differentiation.

- Metaplasia is not synonymous with dysplasia and is not directly considered carcinogenic. It is also contrasted with heteroplasia, which is the abnormal growth of cytologic and histologic elements without a stimulus.

 

 

 

 

 
 
 

 
 
 

Epithelial metaplasia - focal areas of transformed urothelium with normal nuclear and cellular architecture surrounded by normal urothelium usually located on the trigone
 

① Squamous metaplasia 

  - Nonkeratinizing squamous metaplasia
  - Keratinizing squamous metaplasia

② Glandular metaplasia

Squamous Metaplasia

Nonkeratinizing squamous metaplasia 
• Present in 85% of reproductive-age women and 75% of menopausal women in trigone where it's considered a normal (non-metaplastic) finding; occurrence outside this area is considered metaplastic.
• May cause urinary urgency/frequency (pseudomembranous trigonitis), but has no risk for progression to neoplasia.
• Also seen in male receiving hormonal therapy for prostate cancer.
• Histology: squamous cells usually have bubbly appearance due to accumulation of glycogen that produces cytoplasmic clearing

 

  

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
•In the past, keratinizing squamous metaplasia of bladder was thought be associated with concurrent or subsequent carcinomas with squamous differentiation, and suggested as precursor lesion for squamous cell carcinoma.
 --> but this notion is changed after publication of journal that keratinizing squamous metaplasia lacks p53 mutation.
•Cytogenetic studies on bladder keratinizing squamous metaplasia (leukoplakia) are consistent with a benign lesion, and no treatment is necessary.

 

 

 

 

 

 

Glandular Metaplasia

- Clumps of raised red areas that appear inflammatory and are often confused for cancer.
- Glandular metaplasia can extensively involve the bladder, particularly the trigone, but biopsy is not required. Treatment is unnecessary, and a preventive agent has not been identified.

PPT :  Epithelial Metaplasia of Bladder.ppt

Benign Tumors of the Bladder Classification

Benign Tumors of the Bladder

 

Classification 

 

  1) Epithelial Metaplasia

  2) Leukoplakia

  3) Inverted Papilloma

  4) Papilloma

  5) Nephrogenic Adenoma

  6) Cystitis Cystica and Glandularis

  7) Leiomyoma