Melanoma is a cancer of melanocytes — pigment cells of the skin. Less common than BCC or SCC but the form of skin cancer most likely to spread. Early melanomas (in situ and thin invasive <1 mm) have very high cure rates with proper surgery. Thicker melanomas are co-managed with a specialist.
- Melanoma is a cancer of pigment cells (melanocytes).
- Earliest forms — melanoma in situ and thin invasive melanoma — have very high cure rates.
- Breslow thickness on histology is the most important prognostic factor.
- Treatment for early melanoma is wide local excision with an appropriate margin.
- Scans and sentinel lymph node biopsy are reserved for higher-risk cases — not routinely done for thin melanomas.
- Lifelong skin surveillance is important — a first melanoma indicates higher risk of a second.
Melanoma
Melanoma is a cancer that begins in the pigment cells of the skin (melanocytes). It is less common than basal cell carcinoma or squamous cell carcinoma, but earns particular attention because it is the form of skin cancer most likely to spread if left untreated. The good news is that the earliest forms — melanoma in situ and thin invasive melanoma — have very high cure rates when detected early and properly excised.
By Dr Christopher Irwin, MBChB, FRACGP, MMed (Skin Cancer), FACAM, ASCD
Last reviewed 2026-06-06 · Editorial policy
Melanoma is a cancer that begins in melanocytes, the cells that produce pigment in the skin. It earns special attention because it is the form of skin cancer most likely to spread elsewhere in the body if left untreated. The good news is that early melanomas are highly curable — and most melanomas we see at The Skin Doctor are caught at an early stage thanks to skin checks and patient self-examination.
The Melanoma Family
We use the term “melanoma family” to describe the spectrum from earliest to more advanced disease. Two early forms are described in their own patient pages:
- Melanoma in Situ (Stage 0) — melanoma cells confined to the epidermis. Essentially no risk of spread.
- Thin Invasive Melanoma — Breslow thickness under 1 mm. Low but not zero risk of spread; excellent prognosis with wide local excision.
Thicker melanomas (≥1 mm) and ulcerated, high-mitotic-rate or node-positive melanomas need more intensive treatment and follow-up, and are co-managed with a melanoma specialist team.
Why Early Detection Matters
The most important determinant of melanoma outcome is the Breslow thickness — the measured depth of invasion in millimetres on the pathology slide. A 1 mm melanoma is the thickness of a grain of sand. Catching melanomas at that depth or less is the goal of every skin check we do.
Patients diagnosed with one melanoma carry roughly a 9× increased risk of a second primary melanoma compared with matched controls, greatest in the first two years after diagnosis. That is why we see patients regularly after diagnosis — typically every 3 months for the first two years, then gradually less often as time passes without recurrence or new melanomas.
Imaging at The Skin Doctor
We use world-leading imaging to find and monitor pigmented lesions:
- VECTRA® WB360 3D total-body imaging at our Diamond Creek clinic.
- IntelliStudio® 2D total-body imaging at our Ivanhoe clinic.
- D200evo and VEOS digital dermatoscopes — high-magnification cross-polarised imaging integrated with DermaGraphix® software.
Sun Protection and Lifestyle
Reducing future UV exposure is one of the best things you can do for yourself after a melanoma diagnosis. Daily broad-spectrum SPF 50+ on exposed skin, hats, protective clothing, and avoidance of solariums all help. We also recommend monthly self skin examination and prompt assessment of any new or changing lesion.
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Symptoms
- A new mole appearing in adulthood
- A mole that is changing or evolving
- Asymmetry of a mole
- Varied colour within a single spot
- A mole larger than your other moles
- An "ugly duckling" lesion that stands out from your other moles
Causes & contributors
- Ultraviolet (UV) radiation from sunlight and solariums
- Fair skin, light eyes, red or blonde hair, easy freckling
- Personal or family history of melanoma
- Large number of moles or multiple dysplastic naevi
- Significant childhood sunburns
- Immunosuppression (eg. organ transplant, certain medications)
Diagnosis
Diagnosis is made on a biopsy. Suspicious lesions are usually removed in full (excisional biopsy) so the pathologist can examine the whole lesion. The histology report names the type of melanoma and describes key features — most importantly the Breslow thickness (depth of invasion), whether there is ulceration, mitotic rate, Clark level and lymphovascular invasion. These features determine staging and management.
Treatment options
Wide local excision
Once melanoma is confirmed, the area is re-excised with a safety margin of normal skin around the original scar. The margin depends on the Breslow thickness — typically 5 mm for melanoma in situ and 1 cm for thin invasive melanoma up to 1 mm.
Sentinel lymph node biopsy
Discussed for selected thin melanomas with high-risk features (Breslow 0.7–1 mm with ulceration, mitotic rate >1, Clark level IV/V or lymphovascular invasion) and for thicker melanomas. Not routinely recommended for very thin or in situ melanoma.
Specialist referral
Thicker, ulcerated or advanced melanomas are co-managed with a melanoma specialist or surgical oncology team — including consideration of immunotherapy or targeted therapy where indicated.
Long-term skin surveillance
All melanoma patients are followed with regular full skin checks. A first melanoma is associated with a roughly 9× increased risk of developing a second primary melanoma, so vigilance matters.
Sun protection
Daily broad-spectrum SPF 50+, protective clothing, hats and avoidance of solariums. Sun protection lowers the risk of new primary melanomas.
When to see a doctor
See a doctor promptly if a mole is new in adulthood, changing, asymmetrical, varied in colour, larger than your other moles or evolving in any way. The "ugly duckling" lesion that stands out from the rest of your moles is a useful sign. Earlier diagnosis means thinner tumours and better outcomes.
Frequently asked questions
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Is melanoma always serious?
Melanoma earns particular attention because it is the form of skin cancer most likely to spread elsewhere in the body if left untreated. The reassuring news is that the earliest forms — melanoma in situ and thin invasive melanoma — have very high cure rates when detected early and properly excised. Most melanomas we see at The Skin Doctor are caught at an early stage thanks to skin checks and self-examination.
-
How is melanoma diagnosed?
Diagnosis is made on a biopsy. Suspicious lesions are usually removed in full as an excisional biopsy, so the pathologist can examine the whole lesion. The histology report then names the type of melanoma and describes key features that determine staging and management.
-
What is Breslow thickness and why does it matter?
The Breslow thickness is the measured depth of invasion in millimetres on the pathology slide, and it is the most important determinant of melanoma outcome. To put it in perspective, a 1 mm melanoma is about the thickness of a grain of sand. Catching melanomas at that depth or less is the goal of every skin check we do.
-
How is early melanoma treated?
Once melanoma is confirmed, the area is re-excised with a safety margin of normal skin around the original scar — this is called wide local excision. The size of the margin depends on the Breslow thickness, typically 5 mm for melanoma in situ and 1 cm for thin invasive melanoma up to 1 mm. Thicker, ulcerated or advanced melanomas are co-managed with a melanoma specialist team.
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Will I need a sentinel lymph node biopsy or scans?
Not for most thin melanomas. Sentinel lymph node biopsy is discussed for selected thin melanomas with high-risk features and for thicker melanomas, but it is not routinely recommended for very thin or in situ melanoma. Scans and node biopsy are reserved for higher-risk cases rather than done routinely.
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If I have had one melanoma, am I at risk of another?
Yes. Patients diagnosed with one melanoma carry roughly a 9× increased risk of a second primary melanoma compared with matched controls, and this risk is greatest in the first two years after diagnosis. That is why we see patients regularly afterwards — typically every 3 months for the first two years, then gradually less often as time passes without recurrence or new melanomas.
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What can I do to lower my risk after a melanoma diagnosis?
Reducing future UV exposure is one of the best things you can do for yourself. We recommend daily broad-spectrum SPF 50+ on exposed skin, hats, protective clothing and avoidance of solariums. We also advise monthly self skin examination and prompt assessment of any new or changing lesion.
-
When should I see a doctor about a mole?
See a doctor promptly if a mole is new in adulthood, changing, asymmetrical, varied in colour, larger than your other moles, or evolving in any way. The ugly duckling lesion that stands out from the rest of your moles is a useful warning sign. Earlier diagnosis means thinner tumours and better outcomes.
References
- Clinical practice guidelines for the diagnosis and management of melanoma. Cancer Council Australia & Melanoma Institute Australia.
- Cutaneous melanoma. Lancet. 2023. (Long GV, Swetter SM, Menzies AM, Gershenwald JE, Scolyer RA.)DOI: 10.1016/S0140-6736(23)00821-8
- NCCN Guidelines Insights — Melanoma (Cutaneous), Version 2.2024. J Natl Compr Canc Netw. 2024.DOI: 10.6004/jnccn.2024.0036
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Medically reviewed by Dr Christopher Irwin, MBChB, FRACGP, MMed (Skin Cancer), FACAM, ASCD · Last reviewed 2026-06-06 · Editorial policy