The three TNM components
- T — primary tumour
- For cutaneous melanoma, this mainly reflects Breslow thickness and ulceration.
- N — regional spread
- Describes regional lymph-node involvement and regional skin or subcutaneous metastases.
- M — distant metastases
- Indicates spread to distant sites.
Stages at a glance
- 0: melanoma in situ, confined to the epidermis.
- I–II: melanoma localised to the skin without evidence of regional or distant spread; subcategories depend on tumour features.
- III: regional spread to lymph nodes and/or other regional sites defined by the classification.
- IV: distant metastases.
How stage is established
The doctor combines histology, examination and investigations appropriate to the individual case. Sentinel lymph-node biopsy and imaging are not needed in every situation. Ask whether your stage is clinical or pathological and whether results are still pending.
Prognosis: interpreting figures
Statistics describe groups of patients and depend on the period, population and treatments studied. They cannot give an individual percentage based on stage alone. Historical tables and percentages previously displayed here have been removed because they should not be used to describe an individual’s current outlook.
Sources and update
- Cancer Research UK — Stages and types of melanoma
- National Cancer Institute — Melanoma treatment, PDQ
Editorial update: 16 October 2026. This information provides guidance and does not replace a medical assessment.