A spot that looks slightly darker than it did last summer can be easy to explain away. It may be a harmless mole, freckle, sunspot or another benign mark. But when it comes to melanoma versus pigmented lesion, appearance alone is not enough to make that call. In Australia, where ultraviolet radiation is intense and skin cancer is common, a changing or unusual spot deserves timely clinical assessment.
A pigmented lesion is a broad term for a coloured mark on the skin. Melanoma is one possible diagnosis within that broad group, and it is the diagnosis doctors must not miss. Most pigmented lesions are not melanoma. The challenge is that an early melanoma can resemble an ordinary mole, while some harmless lesions can look worrying. Knowledge can save your life, but diagnosis requires a trained clinician and, sometimes, a biopsy.
Melanoma versus pigmented lesion: what is the difference?
Pigment is the colour made by melanin. A pigmented lesion may be brown, black, tan, blue-grey, red-brown or a mixture of colours. Common examples include freckles, moles, solar lentigines, seborrhoeic keratoses and age-related sunspots. Some are present from childhood; others develop after years of sun exposure.
Melanoma is a cancer that develops from melanocytes, the cells that produce melanin. It may begin in an existing mole or arise as a new lesion on previously normal skin. Although many melanomas are dark or unevenly coloured, not all are. Amelanotic melanoma may appear pink, red or skin-coloured, so a spot does not need to be brown or black to warrant attention.
The key distinction is not whether a mark contains pigment. It is whether the cells within it are behaving abnormally and have the potential to invade deeper tissue and spread elsewhere in the body. That cannot be determined reliably from a photo, a memory of what the spot used to look like, or an online checklist.
Why change matters more than a single feature
Many harmless moles are symmetrical, evenly coloured and stable for years. However, no individual sign proves a lesion is safe. Some melanomas are small, symmetrical or only one colour, particularly early on.
For this reason, doctors look closely at change over time. A spot that is new in adulthood, growing, becoming darker, developing several colours, changing shape, crusting or bleeding should be checked. So should a lesion that feels different from the others, such as one that is persistently itchy, tender or painful.
The ABCDE guide can help you notice concerning changes:
- A – Asymmetry: one half does not resemble the other.
- B – Border: edges are irregular, blurred, scalloped or uneven.
- C – Colour: there are multiple colours or an unusual shade.
- D – Diameter: the spot is growing, especially if it is larger than about 6 mm.
- E – Evolving: it changes in size, shape, colour, surface or sensation.
Diameter is useful, but it is not a safety threshold. Melanomas can be smaller than 6 mm. Evolution is often the most useful clue because it captures what you know best: whether a particular spot is behaving unlike it used to.
Another practical tool is the ugly duckling sign. Look for a mole or lesion that stands out from the pattern of marks on your own body. If most of your moles look similar and one is distinctly darker, larger, pinker, rougher or more irregular, arrange a skin check. Your skin has its own pattern, and a lesion that breaks that pattern deserves attention.
Features that need prompt medical review
Book a skin check promptly if you notice a new or changing pigmented lesion. Do not wait to see whether it settles if it is evolving over weeks or months. Seek urgent medical advice for a lesion that bleeds without being injured, develops a persistent sore or ulcer, becomes rapidly raised, or changes noticeably over a short period.
Melanoma is not limited to the places that receive the most sun. Check the scalp, ears, neck, back, buttocks, soles of the feet, palms, between the toes and under the nails. A dark streak in a nail that is new, widening, irregular or extending onto the surrounding skin should be assessed. Ask a partner, family member or friend to help inspect difficult areas such as your scalp and back.
People with darker skin can develop melanoma too, including on the palms, soles and beneath nails. Lower risk is not no risk. Any persistent changing lesion, regardless of skin tone, should be reviewed.
How a clinician tells the difference
A skin cancer clinician, GP or dermatologist will ask when you first noticed the lesion and whether it has changed. They will examine it under good lighting and may use a dermatoscope, a handheld device that magnifies the skin and reveals structures not visible to the naked eye.
Dermoscopy improves assessment, but it does not replace pathology where there is genuine concern. If a lesion looks suspicious, the clinician may recommend removing all or part of it for laboratory examination. A pathologist then examines the cells under a microscope to determine whether melanoma is present and, if so, its type and thickness.
This process can feel unsettling, particularly when the lesion turns out to be harmless. But the trade-off is clear: early melanoma is often highly treatable with surgery, while a delayed diagnosis can allow the cancer to grow deeper and spread. A biopsy is not an overreaction when clinical features raise concern. It is the most reliable way to get an answer.
Your risk changes the threshold for action
Anyone can develop melanoma, but some Australians need a lower threshold for regular professional checks. Risk is higher for people with fair skin that burns easily, many moles, atypical moles, a personal history of melanoma or other skin cancers, or a close family history of melanoma. Significant sun exposure, repeated sunburn, outdoor work and use of tanning beds also add risk.
People taking medicines that suppress the immune system should speak with their treating clinician about an appropriate skin surveillance plan. So should people who have previously had a suspicious lesion removed. The right interval varies. Some people may need frequent checks, while others may be advised to attend annually or to seek assessment only when they notice a change.
A professional skin check does not mean you should stop looking at your own skin. Between appointments, take note of your usual moles and use photographs, taken in consistent lighting, to help identify change. Photos are a record, not a diagnosis, and should never delay an appointment for a concerning spot.
What to do while you wait for an appointment
Do not pick, scratch or attempt to remove a lesion yourself. Avoid treating a changing spot with home remedies, wart preparations or cosmetic products. These can irritate the area and make proper assessment more difficult.
Write down when you first noticed the lesion, what has changed and whether it has bled, itched or become sore. If possible, take a clear photograph for your own reference. Then arrange an assessment with a qualified clinician experienced in skin cancer detection.
Continue to protect your skin from ultraviolet radiation. Use broad-spectrum, water-resistant SPF 50+ sunscreen correctly, wear protective clothing, a broad-brimmed hat and sunglasses, and seek shade where practical. Sun protection reduces further damage, but it does not make an existing suspicious lesion disappear.
A timely check can change the outcome
It is understandable to feel anxious about a changing mole, especially after hearing the word melanoma. Most lesions assessed in clinics are not melanoma. That reassurance, however, should come from an examination rather than guesswork.
If a spot is new, changing or simply does not look right to you, make the appointment. Every minute counts when a melanoma is developing, and a timely skin check can provide either early treatment or the peace of mind to move forward.