Cancer, pigmentation, hair and nails
Skin cancer
Approach to a suspicious lesion
History: evolution, bleeding, itch/pain, previous skin cancer, sun exposure, immunosuppression and family history. Examine the entire skin when appropriate and regional nodes. Use dermoscopy if trained; photograph and measure with consent.
- Australia and New Zealand have the highest reported melanoma incidence and mortality in the world (1).
- Actinic keratoses are marker lesions of sun damage; field treatment (e.g. topical creams) or lesion-directed treatment such as cryotherapy are options (4).
Melanoma warning features
ABCDE: asymmetry, border irregularity, colour variation, diameter/change and evolution. Also consider the “ugly duckling,” a new or changing lesion, nodular EFG pattern (elevated, firm, growing) and amelanotic melanoma.
- Mnemonic, BITCHES (suspect malignancy in melanoma): Bleeds, Irregular / Itch, Tender, Colour change, Halo, Enlargement, Satellite lesions.
- DermNet: ABCDE = Asymmetry, Border irregularity, Colour variation, Different (formerly diameter), Evolving; nodular melanoma EFG = Elevated, Firm, Growing. Not all melanomas follow ABCD; the Glasgow 7-point checklist is an alternative (1). Suspicious melanoma generally requires prompt complete excision biopsy with a narrow clinical margin where feasible; avoid destructive treatment.
Basal cell carcinoma
Common, usually slow-growing and rarely metastatic but locally destructive. Nodular lesions may be pearly with telangiectasia or ulceration; superficial lesions are scaly; morphoeic lesions resemble scar and have ill-defined margins. Treatment depends on site, subtype, size and patient factors and may include excision, Mohs surgery or selected non-surgical therapies.
- Histological subtypes include nodular, superficial and infiltrative (morphoeic); pathology reports deep and lateral margins and incomplete excision warrants further surgery (2). Mohs micrographic surgery is used for high-risk sites/subtypes (2).
Squamous cell carcinoma
Often a rapidly growing, tender, firm or hyperkeratotic lesion on sun-exposed skin. Risk rises with immunosuppression, chronic wounds and high-risk lip/ear sites. Bowen disease is SCC in situ. Prompt biopsy/excision and risk stratification are required; assess regional nodes in high-risk disease.
- High-risk cutaneous SCC features include diameter 2 cm or more and location on the ear, lip vermilion, central face, hands, feet or genitalia (3). Bowen disease = intraepidermal SCC (3).
Management and follow-up
Histology determines diagnosis, Breslow thickness and margins. Definitive excision margins, sentinel-node assessment, imaging and systemic therapy are specialist/stage dependent. Counsel on sun protection, self-examination and follow-up for recurrence and additional primary cancers.
- Melanoma excision margins (Australian Clinical Practice Guidelines 2018 as quoted by DermNet): in situ 5 mm; under 1 mm 10 mm; 1-2 mm 10-20 mm; 2-4 mm 10-20 mm; over 4 mm 20 mm (1).
- Sentinel node biopsy is recommended in Australia/NZ for melanoma thicker than 1 mm, or over 0.75 mm with other high-risk features; it helps staging and adjuvant therapy decisions but does not improve survival (1). Breslow thickness is the strongest predictor of outcome (1).
Notes
Last updated from Sen’s notes on 9 October 2026.