TNM system for urothelial cancer

The TNM system for classifying urothelial cancer is organised as shown below:

Tumour:

• Tis: carcinoma in situ
• T1: no palpable tumour:
  • pTa: tumour confined to epithelium
  • pT1: invasion of subepithelial connective tissue
• T2: no mass or thickening palpable:
  • pT2: invasion of superficial bladder muscle
• T3: palpable hard, mobile mass:
  • pT3a: invasion of deep muscle (outer half)
  • pT3b: invasion beyond bladder wall:
    • pT3bI: microscopically
    • pT3bII: macroscopically
• T4: palpable hard, fixed mass:
  • pT4a: invasion of prostate, uterus, vagina
  • pT4b: invasion of pelvic wall, abdominal wall

Nodes:

• No - no nodal involvement
• N1 - single ipsilateral regional node
• N2 - contralateral or multiple regional nodes
• N3 - fixed regional nodes
• N4 - extra-regional nodes
• Nx - nodal status not known

Metastases:

• M0 - no metastases evident
• M1 - metastases present
• Mx - metastatic status not known