Urothelial Cell Carcinoma

Overview
  • Urothelial Cell Carcinomas (UCCs) originate from urothelial cells that compose the urothelium of the renal pelvis, calyces, ureters, bladder and proximal two-thirds of the urethra. Although, UCCs can occur at any of these locations, nearly 90% occur in the bladder followed by 8% in the renal pelvis. It should be pointed out that 90% of bladder cancers are UCCs with a very small minority being of other morphologies. Therefore, for all intensive purposes, bladder cancer can be thought of as UCC occurring within the bladder.
Morphology
  • Overview
    • UCCs are carcinomas and are categorized according to their pattern of growth, level of invasion, and cellular characteristics.
  • Growth Pattern
    • Papillary: Tumor can be seen grossly as a red excrescence on the urinary tract wall. Tumors grow in an exophytic pattern and display finger-like projections attached by a fibrovascular stalk.
    • Flat: Tumor may be visible only as a patch of redness on the urinary tract wall.
  • Invasion
    • Non-invasive: Tumors that have not grown past the epithelial basement membrane and display a "flat" morphology (see above) are considered carcinoma in situ
    • Invasive: Invasion past the epithelial basement membrane, lamina propria, and into the detrusor muscle is associated with a much worse prognosis
  • Cellular Characteristics
    • Tumor cells can range widely in their characteristics from being nearly indistiguishable from normal urothelial cells to displaying extreme atypia and anaplasia.
Clinical Consequences
  • Symptomology
    • Hematuria: The vast majority of UCCs present with hematuria which is often the only symtpom
    • Urinary Tract Obstruction: Depending on the location of the tumor and its size, obstruction of the urinary tract may occur with attendant symptomology (see page).
  • Course
    • UCCs are malignant and can metastasize.
Risk Factors
  • The risk of developing UCC, especially in the bladder increases significantly with a prominent smoking history. It is thought that the bladder urothelium in smokers is exposed for long periods of time to renaly-excreted cigarette carcinogens prior to voiding. Additionally those with industrial exposure to napthylamine and aniline dyes as well as patients who have undergone long-term and heavy use of cyclophosphamide are at increased risk.