TNM staging
By Mia Wangsmo Steffenssen MD, Mike Mikkelsen Lorenzen, MD and Pia Sjøgren MD
Anatomic stage/prognostic groups
| Primaty tumor (T) | |
| Tx | Primary tumor cannot be assessed (ie, curretaged or severely regressed melanoma) |
| T0 | No evidence of primary tumor |
| Tis | Melanoma in situ |
| T1 | Melanoma ≤ 1.0 mm in thickness T1a: Without ulceration and mitoses <1/mm² T1b: With ulceration or mitoses ≥1/mm² |
| T2 | Melanomas 1.01-2.0mm in thickness T2a: Without ulceration T2b: With ulceration |
| T3 | Melanomas 2.01-4.0 mm in thickness T3a: Without ulceration T3b: With ulceration |
| T4 | Melanomas > 4.0 mm in thickness T4a: Without ulceration T4b: With ulceration |
| Regional lymph nodes (N) | |
| Nx | Patients in whom the regional nodes cannot be assessed (ie. previously removed for another reason) |
| N0 | No regional metastases detected |
| N1-3 | Regional metastases based upon number of metastatic nodes and presence or absence of intralymphatic metastases (in transit or satellite metastases) |
| N1 | 1 lymph node N1a: Micrometastases N1b: Macrometastases |
| N2 | 2 or 3 lymph nodes N1a: Micrometastases N1b: Macrometastases N2c: In-transit met(s)/satellite(s) without metastatic lymph nodes |
| N3 | ≥ 4 metastatic lymph nodes, or matted nodes, or in-transit met(s)/satellite(s) with metastatic lymph node(s) |
| Distant metastasis (M) | |
| M0 | No detectable evidence of distant metastases |
| M1a | Metastases to skin, subcutaneous, or distans lymph nodes, normal serum lactate dehydrogenase (LDH) level |
| M1b | Lung metastases, normal LDH level |
| M1c | Metastases to all other visceral sites or distant metastases to any site combined with an elevated serum LDH level |
