Most melanoma advice tells you to watch for a dark, changing mole with the ABCDE signs. But two of the most dangerous melanomas break those rules — nodular and amelanotic melanoma. They are the ones most often missed, because they do not look like what people (or even doctors) expect. Here is what they actually look like, and how to get a spot reviewed if you are unsure.
Related: What To Expect From an Online Skin Check.
Why these two get missed
The familiar ABCDE rule was built around the most common melanoma, which spreads slowly across the surface as a flat, dark, irregular patch. Nodular and amelanotic melanomas do not fit that picture — so people wait, and they are often found later, when they are harder to treat. Knowing what else to look for is the whole point.
Nodular melanoma: a firm lump that is growing
Nodular melanoma usually appears as a raised, firm bump rather than a flat spot. It is often a single, even colour (it can be blue-black, dark brown, or red to skin-coloured), and fairly symmetrical — so it may pass the ABCDE test and still be dangerous. What gives it away is growth: it enlarges over weeks to a few months, and may bleed, crust or feel firm.
A simpler rule fits it better — EFG:
- E – Elevated: raised above the skin.
- F – Firm: solid to touch.
- G – Growing: getting bigger over about a month.
Any new firm bump that keeps growing is worth checking — do not wait for it to turn dark or develop “classic” features.
Amelanotic melanoma: the one with little or no colour
“Amelanotic” means it makes little or no dark pigment, so it can be pink, red or skin-coloured instead of brown or black. Because there is no dark spot to trigger alarm, it is easily mistaken for a harmless pimple, a scratch that will not heal, a patch of dermatitis, or a basal cell carcinoma. Watch for a pink or red spot that grows, bleeds, itches, or simply refuses to heal over several weeks.
The rules that still work
- The ugly-duckling sign: a spot that looks or behaves differently from your others is worth checking, even without textbook features.
- New, growing, firm, changing, bleeding or not healing — regardless of colour. This single habit catches the melanomas the ABCDE rule misses.
Why acting early matters
Caught early, melanoma is usually removed with simple surgery and is very treatable. Nodular melanoma in particular can grow deeper quickly, so a firm, growing lump is worth seeing sooner rather than watching for months. When in doubt, get it looked at — that decision matters more than any checklist.
Get a spot reviewed
Use Skin360AI to keep photos of the spots you want to watch connected over time. A spot can be a mole, freckle, mark, lump, sore, patch or any skin area. A photo record is not a diagnosis or an all-clear. If a spot is new, changing, bleeding, painful, growing, not healing or worrying you, arrange an in-person GP or skin-cancer clinic assessment. Related: what melanoma looks like and is my mole skin cancer?
This is general information, not a diagnosis, and a photo cannot rule skin cancer in or out. Anything new, growing, firm, changing, bleeding or not healing should be seen in person by your GP or a skin-cancer clinic — whatever colour it is.