How do you spot melanoma, and how fast does it grow?
You can spot a melanoma as a mark that changes or looks different from the others, using the ABCDE signs: asymmetry, border, color, diameter, evolving. Its speed depends on the type: 0.12 mm a month for superficial spreading, 0.49 mm for nodular (medians, Liu, 2006). At stage IA, 98% of patients are alive after 10 years (Gershenwald, 2017).
Simplified drawings, not to scale, with no patient photos. Dotted lines are estimates between measured points.
How does a melanoma grow?
A cross-section of skin, from one cell that changes to the lymph nodes. Choose a type of melanoma; tap a label to learn what it is.
On the keyboard: 1 to 3 melanoma types, Space pause, L slow motion, R restart, ← → previous or next step.
Sources: stages and survival (Gershenwald, 2017, stages I to III, patients treated since 1998); stage IV (Wolchok, 2025); speed (Liu, 2006, based on what 404 patients remembered; lines and durations calculated); genes and UV (TCGA, 2015; Hayward, 2017); margins (Falk Delgado, 2019). Group averages: they do not predict any one case.
How do you spot a mark worth showing a doctor?
The ABCDE signs, one by one, on a drawing. Having a sign does not mean cancer: it means the mark is worth having checked.
Sources: ABCDE (Abbasi, JAMA, 2004); ugly duckling (Grob and Bonerandi, 1998); nodular, raised, less often pigmented (Chamberlain, 2003). Drawings made for this page, not patient photos. They cannot be used to make a diagnosis.
What changes the risk of melanoma?
How many times the risk is multiplied, with its margin of uncertainty. Tap a row to read the details. A relative risk is not the probability of getting sick.
Sources: moles (Gandini, part I, 2005); family (Gandini, part III, 2005); sunburns and intermittent sun (Gandini, part II, 2005, figures read from the author's slides, to be verified); tanning beds (Boniol, 2012); sunscreen (Green, 2011); risk per mole (Tsao, 2003).
Frequently asked questions about melanoma
How can you tell if a mole is a melanoma?
Only an exam can tell, and if needed a look under the microscope at the removed spot. The ABCDE signs (asymmetry, border, color, over 6 mm, evolving) and the ugly duckling only tell you which spot to show a doctor (Abbasi, 2004; Grob and Bonerandi, 1998).
Can a mole turn into a melanoma?
Yes, but it is rare, and it is not the most common case: 29.1% of melanomas start in an existing mole, 70.9% on skin with no mole (Pampena, 2017). Per mole and per year, the risk is 1 in 200,000 or lower before age 40 (Tsao, 2003).
Can people with dark skin get melanoma?
Yes, even though it is rarer: often fewer than 1 case per 100,000 people in Africa and Asia, compared with 42 in men and 31 in women in Australia and New Zealand (Arnold, 2022). The acral type affects the sole, the palm or the nails: it makes up 36% of melanomas in Black people in the United States (Bradford, 2009).
How fast does a melanoma grow?
It all depends on the type: at the median, 0.12 mm a month for superficial spreading and 0.49 mm for nodular. A third of the melanomas in the study grew 0.5 mm a month or more (Liu, 2006, 404 patients). These speeds rely on what patients remembered: they give a rough idea.
How is melanoma treated?
The spot is removed with a margin: 5 mm for a melanoma in situ, 1 cm under 1 mm thick, 1 to 2 cm beyond that. A sentinel node biopsy should be offered from T1b (Falk Delgado, 2019). At advanced stages, immunotherapy has changed the numbers: 43% alive at 10 years with the combination studied (Wolchok, 2025).
True or false?
Most melanomas start in an existing mole.
False. Only about 29% do; 70.9% appear on skin with no mole (Pampena, 2017, 38 studies).
A melanoma can be pink and perfectly round.
True. The nodular type is raised and less often pigmented (Chamberlain, 2003, to be verified), and it may show neither asymmetry nor irregular borders. Change remains the sign to watch for.
The sun explains every melanoma.
False. The UV signature is missing from some skin tumors (76% of primary tumors carry it, TCGA, 2015), and melanomas of the soles, palms and nails mostly have other causes (Hayward, 2017).
This page as text
The same information as the charts, to read without animation: for each chart, the values at the main moments, then the notes with their level of evidence.
How many patients are alive after diagnosis, by stage?
Share of patients who have not died of their melanoma (melanoma-specific survival), at 5 and 10 years. 43,792 patients analyzed for the 8th edition of the staging system, treated from 1998 on (Gershenwald, 2017). Dotted lines: estimate between measured points.
| Years | Stage IA: 99% at 5 years, 98% at 10 years (dotted) | Stage I: 98% at 5 years, 95% at 10 years (dotted) | Stage IIIA: 93% at 5 years, 88% at 10 years (to be verified) (dotted) | Stage II: 90% at 5 years, 84% at 10 years (dotted) | Stage III: 77% at 5 years, 69% at 10 years (dotted) | Stage IIID: 32% at 5 years, 24% at 10 years (to be verified) (dotted) | What happens |
|---|---|---|---|---|---|---|---|
| Diagnosis | 100 | 100 | 100 | 100 | 100 | 100 | At diagnosis |
| 5 yrs | 99 | 98 | 93 | 90 | 77 | 32 | 5 years after diagnosis: measured point |
| 10 yrs | 98 | 95 | 88 | 84 | 69 | 24 | 10 years after diagnosis: measured point |
Key points
- Why does IIIA do better than II? (Throughout, Shown in humans)
A small melanoma with minimal lymph node involvement can do better than a thick melanoma with no node involved. Stages do not read like a simple scale. Source: Gershenwald et coll., « Melanoma staging: Evidence-based changes in the American Joint Committee on Cancer eighth edition cancer staging manual », CA Cancer J Clin, 2017 - No stage 0 or stage IV here (Throughout, Shown in humans)
The article gives no figure for them. Stage IV has its own tab. Source: Gershenwald et coll., « Melanoma staging: Evidence-based changes in the American Joint Committee on Cancer eighth edition cancer staging manual », CA Cancer J Clin, 2017 - How many cases worldwide? (Throughout, Shown in humans)
325,000 new cases and 57,000 deaths in 2020; 510,000 cases and 96,000 deaths projected for 2040. Source: Arnold et coll., « Global Burden of Cutaneous Melanoma in 2020 and Projections to 2040 », JAMA Dermatol, 2022 - Wide gaps within stage III (From 5 years, Shown in humans)
At 10 years, substage IIIA reaches 88% and substage IIID 24%. The 2 figures at 5 years (93% and 32%) are confirmed by Gershenwald; those at 10 years come from a secondary source, to be verified. Source: Gershenwald et coll., « Melanoma staging: Evidence-based changes in the American Joint Committee on Cancer eighth edition cancer staging manual », CA Cancer J Clin, 2017 - Reading these figures (Throughout, Hypothesis)
Averages from large centers. Between measured points, the line is straight: it does not describe what happens year by year.
Has immunotherapy changed advanced melanoma?
Yes: in the CheckMate 067 trial, 945 patients with advanced melanoma received one of 3 treatments, and 43% were alive at 10 years with the combination. Share of patients alive, counting deaths from all causes (overall survival, Wolchok, 2025).
| Years | Nivolumab + ipilimumab: 48% at 7.5 years, 43% at 10 years (estimate between points) (dotted) | Nivolumab: 42% at 7.5 years, 37% at 10 years (estimate between points) (dotted) | Ipilimumab: 22% at 7.5 years, 19% at 10 years (estimate between points) (dotted) | What happens |
|---|---|---|---|---|
| Start | 100 | 100 | 100 | At the start of treatment |
| 2 yrs | 81 | 62 | 46 | 2 years after the start of treatment: estimate |
| 6 yrs | 50 | 43 | 25 | 6 years after the start of treatment: estimate |
| 7.5 yrs | 48 | 42 | 22 | 7.5 years after the start of treatment: measured point |
| 10 yrs | 43 | 37 | 19 | 10 years after the start of treatment: measured point |
Key points
- Half of patients still alive at… (Throughout, Shown in humans)
71.9 months with nivolumab plus ipilimumab, 36.9 months with nivolumab, 19.9 months with ipilimumab, or 6.0, 3.1 and 1.7 years. Source: Wolchok et coll., « Final, 10-Year Outcomes with Nivolumab plus Ipilimumab in Advanced Melanoma », N Engl J Med, 2025 - A plateau (From 3 years, Shown in humans)
Among patients with no progression at 3 years, 96%, 97% and 88% had not died of melanoma at 10 years (melanoma-specific survival). Source: Wolchok et coll., « Final, 10-Year Outcomes with Nivolumab plus Ipilimumab in Advanced Melanoma », N Engl J Med, 2025 - A limitation (Throughout, Shown in humans)
The trial was not designed to formally compare the 2 immunotherapy arms with each other. Source: Wolchok et coll., « Final, 10-Year Outcomes with Nivolumab plus Ipilimumab in Advanced Melanoma », N Engl J Med, 2025 - Do not mix them up (Throughout, Hypothesis)
This tab gives overall survival, the previous tab melanoma-specific survival: the 2 figures cannot be compared directly. - Curves (Throughout, Hypothesis)
Only the points are measured; the lines between them are dotted, as an estimate.
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