Guidelines
Investigation and Diagnosis
Gold standard: skin biopsy for histology
- Preferred: full-thickness incisional biopsy (containing both peripheral and deep margins)
- Large / anatomically challenging area → incisional (punch) biopsy
Management
1st line: standard surgical excision (in resectable primary disease)
Consider Mohs micrographic surgeryThis technique allow layer-by-layer removal of the tumour with real time microscopic examination to ensure: - Maximum removal of cancer cells - Minimal removal of healthy cells - Better functional and cosmetic outcomes after MDT if:
- Tumour margins are not clearly visible / well-defined
- At sites where tissue conservation is important (e.g. eyelid, lips, ears, fingers, genitalia)
- At cosmetically sensitive areas (e.g face)
If surgery not appropriate: primary radiotherapy is an option
Surgical Margins
Peripheral surgical margins (determined under magnification / dermoscopy):
- Low risk tumour → ≥4mm margin
- High risk tumour → ≥6mm margin
- Very high risk tumour → ≥10mm margin
Also ensure at least 1mm histological clearance at all margins.
Tumour Risk Definition
| Low Risk | High Risk | Very High Risk |
|---|---|---|
| ALL the following must be met | ANY of the following | ANY of the following |
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