Melanoma: Symptoms, Diagnosis, and Treatment

What Is Melanoma?

Melanoma is a cancer that develops from melanocytes — the pigment-producing cells in the skin. Although it is less common than basal cell carcinoma and squamous cell carcinoma, melanoma is the most serious form of skin cancer because of its ability to spread (metastasise) to lymph nodes and distant organs if not caught early.

Australia and New Zealand have among the highest melanoma rates in the world, driven by high UV radiation levels and a predominantly fair-skinned population. In Australia, approximately 18,000 people are diagnosed with melanoma each year, and it is one of the most common cancers in people under 40.

The good news: melanoma detected at an early stage — before it has grown deep or spread — is usually curable with surgery. Early detection matters enormously.

Key Points

Melanoma arises from pigment-producing skin cells (melanocytes) and is the most serious form of skin cancer.
Australia has one of the highest melanoma rates in the world — UV radiation is the primary driver.
Early-stage melanoma removed completely is often cured; prognosis worsens with increasing thickness and spread.
The ABCDE rule helps identify suspicious lesions: Asymmetry, Border, Colour, Diameter, Evolving.
Not all melanomas look like typical dark moles — nodular melanoma may be pink or skin-coloured.
Melanoma can occur on any area of skin, including sun-protected areas and under nails.
Treatment for early-stage disease is surgery; advanced melanoma is treated with immunotherapy and targeted therapy.
Regular skin checks and sun protection are the cornerstones of prevention and early detection.
People with risk factors (fair skin, many moles, family history) benefit from regular professional skin checks.

Why Melanoma Matters

It Can Be Serious

Melanoma is disproportionately lethal compared with other skin cancers. When it is detected and removed early — while still thin and localised — the outlook is excellent. When it spreads to the lymph nodes or distant organs, treatment is substantially more challenging, though treatment advances in the last decade (immunotherapy and targeted therapy) have significantly improved outcomes even in advanced disease.

Early Detection Makes a Difference

Tumour thickness at the time of removal is the single strongest predictor of outcome. Thin melanomas (under 1mm, T1) have a ten-year survival rate above 90%. Thick or metastatic melanomas have much lower survival rates. This is the reason regular skin checks and prompt review of suspicious spots are so important.

Not All Melanomas Look the Same

The classic picture of a dark, irregular mole is only one presentation. Melanomas can be:

Superficial spreading melanoma — the most common type; a flat or slightly raised discoloured patch that grows outward before thickening
Nodular melanoma — grows vertically and quickly; may be pink, red, or skin-coloured rather than dark; accounts for a disproportionate number of melanoma deaths because it is often not recognised early
Lentigo maligna melanoma — a flat lesion developing on chronically sun-damaged skin, particularly the face; tends to occur in older adults
Acral lentiginous melanoma — on the palms, soles, or under nails; not related to UV exposure; more common in darker-skinned populations

Warning Signs

The ABCDE Rule

The ABCDE rule guides recognition of suspicious skin lesions:

Letter	Meaning	What to look for
A	Asymmetry	One half looks different from the other
B	Border	Irregular, ragged, notched, or blurred edges
C	Colour	Multiple shades — varying brown, black, red, white, or blue within the same spot
D	Diameter	Larger than 6mm (about the size of a pencil eraser) — though melanomas can be smaller
E	Evolving	Any change in size, shape, colour, or behaviour over weeks to months

Any one of these features warrants prompt review by a clinician.

The Ugly Duckling Sign

The ugly duckling sign is a useful complementary approach: compare a suspicious spot to the other spots on your body. Most people have a consistent “family” of moles. A lesion that looks markedly different from all your others — standing out like an ugly duckling — is more likely to warrant review, regardless of whether it meets all ABCDE criteria.

Other Warning Signs

A new spot or mole in adulthood (particularly after the age of 40)
A mole that bleeds without trauma, or that repeatedly catches on clothing
A spot that itches, crusts, or does not fully heal
A non-healing ulcer or sore on the skin
Nail changes: a dark (brown or black) streak running lengthwise under a nail, particularly if it is widening, irregular, or associated with nail distortion — especially in an adult with no prior nail injury. A dark streak under the nail in a darker-skinned person is more likely to be benign, but unexplained or changing streaks in any person warrant medical assessment.

Risk Factors

Ultraviolet (UV) Radiation

Cumulative UV exposure — from sun and from tanning beds — is the primary driver of melanoma. UV radiation damages the DNA in skin cells. Both UVA and UVB contribute.

Sunburn is a particularly important risk factor. Blistering sunburns in childhood or adolescence significantly increase lifetime melanoma risk, even if sun exposure is reduced in later life.

Tanning Beds

Tanning beds emit UV radiation that causes the same DNA damage as sunlight. Using tanning beds before age 35 increases melanoma risk by approximately 59% (IARC). There is no safe tan from a tanning bed.

Fair Skin and Sun-Sensitive Phenotype

People with fair skin, light or red hair, blue or green eyes, and a tendency to burn rather than tan have higher melanoma risk. This reflects reduced baseline melanin protection in the skin.

Many Moles or Atypical Moles

Having a large number of ordinary moles (more than 50) or atypical (dysplastic) moles — which are often larger than ordinary moles, with irregular edges and variable colour — increases melanoma risk. People with many atypical moles, particularly those with a family history of melanoma, may benefit from regular specialist surveillance.

Family History and Genetics

Approximately 10% of melanomas occur in people with a family history of the disease. Having a first-degree relative with melanoma approximately doubles individual risk. Rare inherited syndromes (including pathogenic variants in CDKN2A, CDK4, and other genes) account for a small proportion of familial cases. Genetic counselling is available for families with multiple melanoma diagnoses.

Personal History of Melanoma or Skin Cancer

A person who has had melanoma has a significantly elevated risk of developing a second melanoma. Lifelong skin surveillance is recommended.

Immunosuppression

People whose immune system is suppressed — including organ transplant recipients, those on long-term immunosuppressive medications, or people with HIV — have a substantially elevated skin cancer risk, including melanoma. Skin checks are particularly important in this group.

Diagnosis

Skin Examination and Dermoscopy

The diagnostic process begins with a thorough skin examination by a GP or dermatologist. A dermoscope — a handheld illuminated magnifier — allows the clinician to visualise structures beneath the skin surface and better assess whether a lesion is suspicious. Dermoscopy improves diagnostic accuracy compared with naked eye examination.

In some settings, total body photography is offered for high-risk patients — photographs of the entire skin surface used as a baseline for tracking changes over time.

Biopsy

Definitive diagnosis requires a biopsy — removal of tissue for laboratory examination. For a lesion suspicious for melanoma:

Excision biopsy (removal of the entire lesion with a small margin) is the preferred approach — it provides the complete lesion for pathological assessment, including thickness measurement.
Punch or shave biopsy may be used when the lesion is large or in a cosmetically sensitive location, though these have limitations because they may not capture the full depth of the lesion.

The biopsy is examined by a pathologist. The pathology report provides the information needed for staging and treatment planning.

The Pathology Report

Key information in the pathology report includes:

Breslow thickness — the depth of the melanoma measured from the top of the granular skin layer to the deepest tumour cell. This is the most important single prognostic factor. Melanomas under 1mm (thin) have an excellent prognosis; those over 4mm (thick) have a substantially worse prognosis.
Ulceration — whether the surface of the melanoma is broken down; worsens prognosis
Mitotic rate — how rapidly tumour cells are dividing
Histological subtype (superficial spreading, nodular, lentigo maligna, acral lentiginous)
Margins — whether the melanoma was removed with clear (cancer-free) edges

Staging

Melanoma is staged using the AJCC (American Joint Committee on Cancer) TNM system. In plain terms:

Stage	Description	Typical Prognosis
Stage 0	Melanoma in situ — cancer cells present only in the outermost skin layer (epidermis)	Virtually 100% cure rate with complete excision
Stage I	Thin, localised melanoma (≤2mm, no ulceration or low mitotic rate)	10-year survival 90%+
Stage II	Thicker or ulcerated localised melanoma, no nodal spread	10-year survival approximately 60–80% depending on subgroup
Stage III	Spread to regional lymph nodes or in-transit metastases (satellite tumours between primary and nodes)	Variable; 10-year survival approximately 40–70% depending on nodal burden
Stage IV	Distant metastases — spread to other organs (lungs, liver, brain, bone, other skin)	Historically poor prognosis; substantially improved with immunotherapy and targeted therapy

Staging determines whether a sentinel lymph node biopsy is recommended and guides decisions about adjuvant therapy after surgery.

Treatment

Surgical Excision

Surgery is the primary treatment for localised melanoma. After a diagnostic biopsy confirms melanoma, a wide local excision is performed — removal of the melanoma site with a margin of surrounding normal tissue. The recommended margin depends on Breslow thickness:

Melanoma in situ: 5–10mm margin
Thin melanoma (<1mm): 10mm margin
Intermediate thickness (1–2mm): 10–20mm margin
Thick melanoma (>2mm): 20mm margin

Achieving clear surgical margins is the goal of definitive surgery.

Sentinel Lymph Node Biopsy

For melanomas of ≥1mm thickness (or thinner melanomas with high-risk features), a sentinel lymph node biopsy (SLNB) may be recommended. This procedure:

Identifies the first lymph node(s) to drain the melanoma site (the sentinel nodes)
Removes these nodes for pathological examination
Determines whether microscopic spread to the lymph nodes has occurred (staging information)
Informs decisions about adjuvant (preventive) systemic therapy

SLNB is a staging procedure, not a curative one — it provides crucial information but does not itself treat melanoma.

Adjuvant (Preventive) Systemic Therapy

For Stage III (and selected Stage II) melanoma, adjuvant therapy after surgery aims to reduce recurrence risk:

Adjuvant immunotherapy — pembrolizumab or nivolumab for resected Stage III disease; significantly reduces recurrence risk
Adjuvant targeted therapy — dabrafenib + trametinib (BRAF/MEK inhibitors) for resected Stage III melanoma with a BRAF V600E or V600K mutation

Immunotherapy for Advanced Melanoma

Immunotherapy has transformed the treatment of advanced (Stage IV) melanoma. Checkpoint inhibitors block the brakes that cancer cells use to evade immune detection:

Pembrolizumab (anti-PD-1)
Nivolumab (anti-PD-1)
Ipilimumab (anti-CTLA-4)
Nivolumab + ipilimumab (combination) — higher response rate but also more side effects

Long-term responses (durable remission in a proportion of patients) have been observed — a major advance compared to chemotherapy.

Targeted Therapy for BRAF-Mutated Melanoma

Approximately 50% of melanomas carry a BRAF V600 mutation. For these tumours, targeted therapy with a BRAF inhibitor combined with a MEK inhibitor produces rapid responses:

Dabrafenib + trametinib
Vemurafenib + cobimetinib
Encorafenib + binimetinib

Targeted therapy is particularly useful when rapid tumour shrinkage is needed. BRAF mutation testing is routine in advanced melanoma.

Radiotherapy

Radiotherapy is used in selected situations:

To treat residual disease at the lymph node basin after surgery
For palliation of symptomatic metastases (bone pain, brain metastases)
Stereotactic radiosurgery (e.g., Gamma Knife) for brain metastases

Palliative and Supportive Care

Palliative care addresses symptoms, quality of life, and emotional wellbeing for people with melanoma at any stage — alongside or instead of tumour-directed treatment. Supportive care can help with symptoms, decisions, and quality of life at different stages, and early palliative care involvement is not only appropriate at end of life.

Follow-Up and Recurrence Monitoring

After treatment for melanoma, ongoing follow-up is important to detect recurrence early and to identify new primary melanomas.

Professional Skin Checks

Regular whole-body skin examinations are recommended for all people who have had melanoma. Frequency varies by stage and risk:

Every 3–6 months for the first 1–2 years
Every 6–12 months thereafter, often lifelong for higher-risk individuals

Dermatologists or specialist skin cancer clinics provide structured surveillance, sometimes using total body photography and digital dermoscopy to track changes over time.

Self-Checking

Learning to examine your own skin between professional checks is important. Check your entire skin surface monthly — including the scalp, between the fingers and toes, soles of the feet, and under nails. Use a mirror or ask a partner to check your back.

Any new or changed lesion between checks should be reviewed promptly rather than waiting for the next scheduled appointment.

Lymph Node Monitoring

After sentinel lymph node biopsy or lymph node surgery, follow-up includes clinical examination of the lymph node regions draining the melanoma site. CT or PET scanning may be used at intervals in higher-stage disease.

Family Awareness

First-degree relatives of someone diagnosed with melanoma should be encouraged to have a baseline skin check and to establish regular sun protection habits. Genetic counselling is appropriate in families with multiple melanoma diagnoses across generations.

Prevention

Sunscreen

Broad-spectrum sunscreen (SPF 30 or higher) applied generously and reapplied every two hours — and after swimming or sweating — reduces UV exposure to skin. Daily sunscreen use, even on cloudy days, reduces cumulative damage. See: Sunscreen: Benefits, SPF Explained, and How It Protects Skin

Protective Clothing and Shade

Long-sleeved shirts and pants provide greater protection than sunscreen alone
Wide-brimmed hats protect the face, neck, and ears
UV-protective sunglasses protect the eyes and periorbital skin
Seeking shade between 10am and 4pm (peak UV hours in Australia) reduces exposure substantially

Avoiding Tanning Beds

Tanning beds increase melanoma risk — there is no safe use of UV tanning equipment. This is particularly important for people under 35.

Skin Checks for Higher-Risk People

People with fair skin, a history of sunburn, many moles, atypical moles, a personal or family history of melanoma, or a history of immunosuppression benefit from regular professional skin checks. The frequency should be discussed with a GP or dermatologist based on individual risk.

See: Skin Cancer — Prevention | Skin Cancer — Warning Signs and Prevention

When to Seek Medical Help

See your doctor promptly for any skin spot or mole that:

Is new or has appeared in adulthood (particularly after age 40)
Has grown, changed shape, or changed colour over weeks to months
Is bleeding without trauma, or bleeds repeatedly
Is persistently itching, crusting, or not healing
Looks different from all your other spots (ugly duckling sign)
Has a dark streak under a nail that is new, widening, or changing in appearance
Is on the palms, soles, or other less sun-exposed areas and is changing

Do not wait for a scheduled appointment if a lesion is changing rapidly — seek review within days to weeks, not months.

FAQ

Q: What does melanoma usually look like? It may appear as a new or changing spot, mole, or patch of skin. Warning signs include asymmetry, irregular borders, uneven colour, change in size, or bleeding. Not all melanomas are dark — nodular melanoma can be pink or skin-coloured.

Q: Can melanoma occur on skin that is not exposed to the sun? Yes. Melanoma is more common on sun-exposed skin, but it can also occur on less exposed areas, under nails, on the soles of the feet, and — rarely — in the eye or mucosal surfaces.

Q: How is melanoma diagnosed? By removing the suspicious spot (excision biopsy) or taking a biopsy, then examining the tissue under a microscope. Dermoscopy helps assess suspicious lesions before biopsy.

Q: Is melanoma treatable? Many melanomas are curable when caught early. Advanced melanoma has been substantially transformed by immunotherapy and targeted therapy, with durable responses in some patients. Early detection remains the most effective strategy.

Q: When should I get a mole checked? Any mole or spot that is new, growing, bleeding, itching, changing, or looks different from your others should be checked promptly. Do not wait — changes over weeks should be reviewed within days to weeks.

Q: Who is at higher risk of melanoma? People with fair skin, history of sunburn, many moles, atypical moles, personal or family history of melanoma, tanning bed use, or immunosuppression are at higher risk and should have regular professional skin checks.

Q: What is the ABCDE rule? A guide to suspicious features: Asymmetry, Border irregularity, Colour variation, Diameter over 6mm, Evolving (changing) appearance. Any one feature warrants medical review.