Melanoma
The most dangerous skin cancer — changing or unusual moles need prompt assessment.
Overview
Melanoma arises from melanocytes, usually in skin but also eye and mucosa. It accounts for a small share of skin cancers but most skin-cancer deaths. Early-stage melanoma is curable by excision; advanced disease has been transformed by immunotherapy (anti-PD-1, anti-CTLA-4) and targeted therapy (BRAF/MEK inhibitors).
Symptoms
- • New or changing mole (asymmetry, border, colour, diameter >6 mm, evolving — ABCDE)
- • Bleeding, itching or ulcerated pigmented lesion
- • New pigmented streak under a nail (subungual)
- • Lump, nodule or amelanotic (pink) lesion that grows quickly
Risk factors
- • Fair skin (Fitzpatrick I–II), red/blond hair, freckling
- • Multiple atypical or >50 melanocytic naevi
- • Personal/family history of melanoma
- • Immunosuppression (transplant, HIV)
Causes
- • Cumulative and intense intermittent UV exposure
- • Sunburn in childhood/adolescence
- • Sunbed use
- • BRAF, NRAS, KIT, CDKN2A mutations
🚨 Red flags — seek urgent care
- • 7-point checklist: change in size, shape, colour, ≥7 mm, inflammation, oozing/bleeding, itch/sensation
- • Subungual streak >3 mm or Hutchinson's sign
- • New nodule with rapid growth
When to seek care
- • Any changing pigmented lesion — 2-week-wait dermatology referral
- • New lesion in adult that does not heal in 4 weeks
- • Family history — discuss baseline skin check
Diagnosis
- • Dermoscopy by trained clinician
- • Excision biopsy with 2 mm margin — never shave/punch a suspected melanoma
- • Breslow thickness, ulceration, mitotic rate guide staging
- • Sentinel lymph node biopsy for melanomas ≥0.8 mm or with ulceration
- • Staging CT/PET-CT and brain MRI for stage III/IV
- • BRAF V600 testing on all stage III/IV tumours
Treatment
- • Wide local excision (margins per Breslow depth)
- • Sentinel node biopsy ± completion node clearance / surveillance
- • Adjuvant therapy (stage III/IV resected): nivolumab, pembrolizumab; dabrafenib + trametinib if BRAF-mutated
- • Metastatic: dual immunotherapy (ipilimumab + nivolumab), targeted therapy (BRAF/MEK), stereotactic radiotherapy for brain mets
- • T-VEC oncolytic therapy for selected unresectable disease
Prevention
- • Daily SPF 30+ broad-spectrum sunscreen; reapply 2-hourly
- • Seek shade 11am–3pm; wear hat, sunglasses, UV-protective clothing
- • Avoid sunbeds entirely
- • Self-examination monthly; annual dermatology review if high risk
Complications
- • Lymphoedema after node dissection
- • Brain, lung, liver, GI metastases
- • Immunotherapy: hypophysitis, thyroiditis, colitis, pneumonitis, hepatitis
- • Second primary melanoma (8% risk)
Prognosis
5-year survival: ~100% stage I, ~80% stage II, ~65% stage III, ~30% stage IV (transformed by immunotherapy from <10%).
Education & self-care
Sun protection from childhood, monthly self-checks and prompt assessment of changing moles are the foundation of melanoma prevention and early cure.
Frequently asked questions
Is every dark mole melanoma?
No — most are harmless. The key is change: new, growing or evolving lesions need review.
Are sunbeds really dangerous?
Yes — use before age 35 increases melanoma risk by ~75%.
Can dark skin get melanoma?
Yes — often acral (palms, soles, nails) and frequently diagnosed late. Be alert to any new pigmented lesion.