Overview of Urinary Bladder Neoplasms



Overview of Urinary Bladder Neoplasms


Jesse K. McKenney, MD

Mahesha Vankalakunti, MD








The spectrum of neoplasia in the bladder includes noninvasive papillary urothelial carcinomas. These may progress to invasive urothelial carcinoma; the risk of progression is related to grade.






Nonpapillary forms of urothelial carcinoma also occur, as demonstrated by this urothelial carcinoma in situ. Progression to invasion may also arise in these flat urothelial carcinomas.


EPIDEMIOLOGY


Incidence



  • 7th most common cancer worldwide



    • 260,000 new cases each year in men


    • 76,000 new cases each year in women


  • In USA, over 90% are urothelial in origin



    • Pure squamous cell carcinoma and adenocarcinoma represent < 5%


  • In regions of endemic schistosomiasis, squamous cell carcinoma is most common


Ethnicity Relationship



  • Highest incidence in Western Europe, North America, and Australia


  • Incidence in developed countries is 6x higher than nondeveloped countries


  • 2x more common in American white men than African-American men


Gender



  • Approximately 3x more common in men than women


Natural History



  • For noninvasive tumors, recurrence and progression rates depend on grade



    • Urothelial papilloma



      • Recurrence: 0-8%


      • Grade or stage progression: 0%


    • Papillary urothelial neoplasm of low malignant potential



      • Recurrence: 25-47%


      • Grade or stage progression: 8%


    • Low-grade carcinoma



      • Recurrence: 48-71%


      • Progression and death due to disease: < 5%


    • High-grade carcinoma



      • Almost all disease-related deaths are secondary to high-grade tumors


      • 40-45% of newly diagnosed bladder cancer is high grade


      • Stage progression: 20% progress to invasion and 12% die of disease


  • For invasive tumors, outcome depends on stage



    • Superficial (pT1)



      • For some patients, conservative management is sufficient


      • Subset will progress to pT2 disease and require cystectomy


    • Invasion of muscularis propria and beyond (greater than pT2)



      • 50% of patients with pT2 or greater disease have occult metastases at diagnosis


      • Most of these develop overt signs of metastasis within 1 year


    • Distant metastasis



      • Very poor prognosis


      • Poor response to adjuvant therapy


Age Range



  • Typically seen in adults



    • More common after 60 years of age


  • In children and adolescents, urothelial papilloma and papillary urothelial neoplasm of low malignant potential may be seen



    • Urothelial carcinoma is extraordinarily rare in young patients


Environmental Factors



  • Tobacco smoking



    • Major established risk factor for bladder cancer



      • 2.6x increased risk in smokers


      • Risk increases with duration and intensity (pack years)


  • Occupational exposure



    • Aniline dye


    • Aromatic amines



      • Benzidine


      • 2-naphthylamine



  • Chronic inflammation



    • Chronic urinary tract infection and calculi proposed as risk factor


  • Other drugs



    • Chronic abuse of analgesics that include phenacetin


    • Cyclophosphamide for cancer therapy


    • Chlornaphazine


Infectious Etiology



  • Schistosomiasis



    • Squamous cell carcinoma


    • Urothelial carcinoma


  • Human papilloma virus



    • Condyloma


    • Squamous dysplasia


    • Squamous cell carcinoma


CLINICAL IMPLICATIONS


Anatomic Considerations



  • Microscopic anatomy of bladder is key to proper staging



    • Lamina propria



      • Connective tissues present between urothelium and detrusor muscle (muscularis propria)


      • Contains loose stroma and variably sized blood vessels


      • Includes thin muscle bands of muscularis mucosae


    • Muscularis propria



      • Thick aggregated muscle bundles of detrusor muscle


    • Perivesical soft tissue



      • Adipose tissue deep to muscularis propria


      • Adipose tissue does not define extravesical location as it is also present in lamina propria and muscularis propria


Intraoperative (Frozen Section) Evaluation

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Jul 7, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Overview of Urinary Bladder Neoplasms

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