Synopsis
Recognise major cutaneous melanoma subtypes, refer suspicious lesions urgently, preserve diagnostic architecture through full-thickness excision biopsy, and interpret Breslow depth as a central staging and management variable.
- Superficial-spreading melanoma often evolves as an irregular multicoloured macule or plaque; nodular melanoma is elevated, firm and rapidly growing and may be uniformly coloured.
- Lentigo maligna melanoma develops within a slowly enlarging irregular macule on chronically sun-damaged head or neck; invasion may arise after a prolonged in-situ phase.
- Acral lentiginous melanoma affects palms, soles or nail units and must be considered in every skin tone; delayed recognition contributes to thicker presentation.
- Refer a lesion urgently when the weighted seven-point score is 3 or more, dermoscopy suggests melanoma, or strong nodular, acral, nail or ugly-duckling concern exists.
- The diagnostic standard is complete full-thickness excision biopsy with a narrow clinical margin where feasible, oriented so Breslow depth and ulceration can be measured.
- Breslow thickness is the vertical distance in millimetres from the top of the granular layer, or ulcer base, to the deepest invasive melanoma cell.
- Do not confuse diagnostic excision with definitive wide local excision; the latter margin is chosen after histological stage is known.
- Palpable nodes or systemic symptoms require specialist staging, but a normal node examination does not exclude microscopic spread.
Key red flags
Rapid nodular growth, ulceration, spontaneous bleeding, acral or nail-unit evolution, palpable nodes, neurological or systemic metastatic symptoms, or a lesion scoring 3 or more on the weighted seven-point checklist requires urgent cancer-pathway assessment.
A firm elevated lesion grows continuously over weeks to months and may be black, brown, red or skin-coloured.
An irregular palm or sole patch or broad changing longitudinal nail band may extend pigment onto adjacent nail-fold skin.
A firm draining-basin node or new dermal nodules between scar and nodal basin suggests regional spread and requires urgent oncology assessment.
Investigation priorities
Identify melanoma-specific pigment, vascular, acral and nail structures and choose the biopsy plan.
Management branches
Clinical or dermoscopic features, evolution, nodular growth or acral or nail change raises melanoma concern.
- Make an urgent suspected-cancer referral with precise site, size, evolution and risk information and suitable consented images if locally supported.
- Leave the lesion intact for specialist dermoscopy and complete full-thickness excision biopsy unless an agreed expert pathway directs otherwise.
- Explain the difference between suspicion and diagnosis, track attendance and safety-net rapid change, bleeding or new nodes.