Overview
Malignant melanoma is a type of skin cancer that originates from melanocytes – the pigment‑producing cells that give skin, hair, and eyes their colour. Although it accounts for only about 1 % of all skin cancers, melanoma is responsible for the majority of skin‑cancer deaths because of its tendency to spread (metastasize) to other organs.
- Who it affects: It can develop at any age, but incidence rises sharply after age 40. Men have slightly higher mortality rates, while women tend to develop melanoma at younger ages.
- Prevalence: In the United States, ~106,000 new cases are diagnosed each year, and about 7,200 people die from the disease (American Cancer Society, 2024). Worldwide, incidence has increased ~3 % per year over the last two decades, with the highest rates in Australia, New Zealand, and Northern Europe (WHO, 2023).
Symptoms
Melanoma often looks like a new mole or a change in an existing one. The “ABCDE” rule helps identify suspicious lesions, but many melanomas do not follow this pattern. Below is a comprehensive symptom list.
Skin‑related signs
- Asymmetry: One half of the mole does not match the other.
- Border irregularity: Edges are scalloped, notched, or blurred.
- Colour variation: Shades of brown, black, red, blue, or white within the same lesion.
- Diameter: Greater than 6 mm (about the size of a pencil eraser); however, some melanomas are smaller.
- Evolving: Any change in size, shape, colour, elevation, or new symptoms such as itching, bleeding, or crusting.
- Surface texture: Raised, warty, or ulcerated.
- Non‑pigmented (amelanotic) melanoma: Appears pink, red, or flesh‑coloured and may be mistaken for a benign lesion.
Systemic signs (usually indicate advanced disease)
- Persistent fatigue or unexplained weight loss.
- Swollen lymph nodes, particularly in the neck, armpit, or groin.
- Persistent cough or shortness of breath (lung involvement).
- Headache, seizures, or neurological deficits (brain metastasis).
- Abdominal pain or jaundice (liver spread).
Causes and Risk Factors
Melanoma arises from DNA damage in melanocytes. The primary cause is ultraviolet (UV) radiation, but genetics and immune status also play major roles.
Major causes
- UV radiation: Both UVA (long‑wave) and UVB (short‑wave) rays cause DNA mutations. Intermittent, intense sun exposure (“sunburns”) is particularly risky.
- Indoor tanning: Tanning beds emit concentrated UVA and UVB; they increase melanoma risk by 20‑30 % (CDC, 2022).
Risk factors
- Fair skin, light hair, and blue or green eyes: Less melanin provides less natural protection.
- Large number of moles (≥50) or atypical/dysplastic nevi: Each mole is a potential site for transformation.
- Personal or family history of melanoma: Approximately 10 % of cases are hereditary.
- Genetic mutations: CDKN2A, BRAF, NRAS, and KIT alterations raise risk.
- History of other skin cancers: Basal or squamous cell carcinoma indicates UV damage.
- Weakened immune system: Organ transplant recipients, HIV/AIDS patients, or those on long‑term immunosuppressants have higher rates.
- Age and gender: Incidence increases with age; men have higher mortality after age 60.
- Geographic location: Living at lower latitudes or at high altitude increases UV exposure.
Diagnosis
Early diagnosis dramatically improves survival—5‑year survival is > 98 % for localized disease but drops to 23 % once distant metastases develop (NIH SEER, 2023).
Clinical evaluation
- Skin examination: A dermatologist performs a full‑body exam, often using a dermatoscope to magnify pigmented lesions.
- ABCD/E rule and pattern analysis: Systematic assessment of asymmetry, border, colour, diameter, and evolution.
Biopsy – the definitive test
- Excisional biopsy: Full removal of the lesion with a narrow margin; preferred for most suspicious lesions.
- Punch or shave biopsy: May be used for very large lesions, but can miss deeper invasion.
- The specimen is examined histologically for depth (Breslow thickness), ulceration, mitotic rate, and other high‑risk features.
Staging investigations (if melanoma is confirmed)
- Sentinel lymph node biopsy (SLNB): Identifies microscopic spread to regional nodes; recommended for tumors > 0.8 mm depth or with high‑risk features.
- Imaging:
- CT of chest/abdomen/pelvis for intermediate‑to‑high‑risk disease.
- PET‑CT for detecting distant metastases.
- MRI of the brain if neurologic symptoms are present.
- Blood tests: Baseline liver function, LDH (prognostic marker), and complete blood count.
Treatment Options
Treatment is guided by tumor stage, location, patient health, and molecular profile.
Surgical management
- Wide local excision: Removes the primary tumour with 1–2 cm margins (depending on thickness). Margins are wider for thicker lesions.
- Sentinel lymph node removal: If the node is positive, a complete regional lymphadenectomy may be performed.
Adjuvant (post‑surgery) therapy
For stage II‑III disease, adjuvant treatment reduces recurrence risk.
- Immune checkpoint inhibitors:
- Anti‑PD‑1 antibodies (nivolumab, pembrolizumab) improve 5‑year recurrence‑free survival to > 60 % (CheckMate 238, NEJM 2022).
- Targeted therapy (BRAF‑mutant melanoma): Combination of BRAF inhibitor (vemurafenib, dabrafenib) plus MEK inhibitor (cobimetinib, trametinib) reduces recurrence and improves overall survival.
- Interferon‑alpha: Older option, now largely replaced by newer immunotherapies.
Advanced (stage IV) disease
- Immunotherapy: Anti‑CTLA‑4 (ipilimumab) alone or combined with anti‑PD‑1; response rates ~ 45 %.
- Targeted therapy: BRAF/MEK inhibitor combos for patients with BRAF V600E/K mutations (present in ~ 40‑50 % of melanomas).
- Oncolytic virus therapy: Talimogene laherparepvec (T‑VEC) – injected directly into cutaneous or nodal lesions.
- Radiation: Palliative for brain or bone metastases.
- Clinical trials: Ongoing studies of novel checkpoint inhibitors, adoptive T‑cell therapy, and personalized vaccines.
Lifestyle and supportive measures
- Smoking cessation – improves response to immunotherapy.
- Regular exercise – helps maintain performance status.
- Nutrition: Adequate protein intake supports wound healing post‑surgery.
- Psychological support – counseling, support groups, and survivorship programs.
Living with Malignant Melanoma
Even after successful treatment, lifelong follow‑up is essential.
Follow‑up schedule
- First 2 years: dermatologist or oncologist visit every 3–6 months.
- Years 3–5: every 6–12 months.
- After 5 years: annual skin exams; more frequent if high‑risk features were present.
Self‑skin checks
- Use a full‑length mirror and a hand mirror.
- Examine every body surface, including scalp, soles, and between toes.
- Document any new or changing lesions with photos.
- Report any suspicious changes promptly to a healthcare provider.
Managing side effects of treatment
- Immunotherapy‑related adverse events: Skin rash, colitis, hepatitis, endocrinopathies. Early detection and steroid therapy are crucial.
- Targeted therapy toxicities: Fever, joint pain, photosensitivity, and secondary skin cancers; dose adjustments may be needed.
- Maintain open communication with the care team—most side effects are manageable when addressed early.
Psychosocial coping
Living with a cancer diagnosis can cause anxiety, depression, and body‑image concerns. Access to mental‑health professionals, melanoma survivor networks, and patient‑advocacy groups (e.g., Melanoma Research Foundation) can improve quality of life.
Prevention
Because UV exposure is the strongest modifiable risk factor, prevention focuses on sun‑safety and regular skin monitoring.
- Sun protection: Apply broad‑spectrum SPF 30+ sunscreen 15 minutes before outdoor exposure; reapply every 2 hours, after swimming or sweating.
- Protective clothing: Wide‑brimmed hats, UV‑protective shirts, sunglasses with 100 % UV blockage.
- Avoid peak UV hours: Seek shade between 10 am–4 pm.
- No indoor tanning: Ban on commercial tanning beds for individuals under 18 in many regions.
- Regular dermatologic screening: At least once yearly for average‑risk adults; more often for high‑risk individuals.
- Education: Teach children and adolescents the “ABCDE” rule early.
Complications
If melanoma is left untreated or is diagnosed at an advanced stage, several serious complications can develop.
- Metastasis: Spread to lymph nodes, lungs, liver, brain, bone, and other organs.
- Ulceration of the primary tumour: Can become infected or bleed.
- Lymphedema: After extensive lymph node surgery, swelling of the arm or leg may occur.
- Second primary cancers: Patients with melanoma have an increased risk of non‑melanoma skin cancers and, occasionally, internal malignancies.
- Psychological impact: Anxiety, depression, and post‑traumatic stress can affect long‑term wellbeing.
When to Seek Emergency Care
Call 911 or go to the nearest emergency department if you notice any of the following:
- Sudden, severe bleeding from a skin lesion that does not stop with gentle pressure.
- Rapid swelling of a lymph node or skin area accompanied by fever.
- New or worsening shortness of breath, chest pain, or persistent cough (possible lung involvement).
- Severe headache, confusion, seizures, or vision changes (possible brain metastasis).
- Unexplained, severe abdominal pain, jaundice, or dark urine (possible liver involvement).
- Any symptom of an allergic reaction (hives, difficulty breathing, swelling of lips or tongue) after receiving immunotherapy or targeted therapy.
Timely emergency evaluation can prevent life‑threatening complications and improve outcomes.
References:
- American Cancer Society. Cancer Facts & Figures 2024.
- World Health Organization. Global Report on Skin Cancer 2023.
- National Cancer Institute SEER Program. Melanoma survival statistics, 2023.
- Mayo Clinic. “Melanoma – symptoms and causes.” Updated 2024.
- Cleveland Clinic. “Melanoma treatment options.” 2024.
- CheckMate 238 Trial. New England Journal of Medicine, 2022.
- Centers for Disease Control and Prevention. “Indoor Tanning and Skin Cancer.” 2022.