Urothelial Cancer Overview

Urothelial (Transitional Cell) Carcinoma

• Malignant tumor originating from the lining of the renal pelvis, ureter, bladder, or urethra
• Most common lower urinary tract cancer, usually arising in the bladder
• Major risk factor: cigarette smoke; other risks include naphthylamine, azo dyes, and long-term cyclophosphamide or phenacetin use
• Typically observed in older adults, characterized by painless hematuria
• Two development pathways:
  • Flat: develops as a high-grade flat tumor, progressing to invasion, commonly associated with early p53 mutations
  • Papillary: initially a low-grade papillary tumor, progressing to a high-grade papillary tumor, and invasion; not typically linked to early p53 mutations
• Frequently multifocal and recurrent ("field defect")

Squamous Cell Carcinoma

• Malignant growth of squamous cells, usually infiltrating the bladder
• Originates in areas of squamous metaplasia (replacement of normal bladder lining with squamous tissues)
• Risk factors include:
  • Chronic cystitis in older women
  • Schistosoma hematobium infection in Egyptian men
  • Long-standing nephrolithiasis

Adenocarcinoma

• Malignant proliferation of glandular tissue, often involving the bladder
• Originates from:
  • Urachal remnants (tumor at the bladder dome)
  • Cystitis glandularis
  • Exstrophy (congenital failure to form the caudal portion of the anterior abdominal and bladder walls)