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Melanoma — SCE Dermatology MCQ

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ModerateDermatological SurgeryMelanomaSCE Dermatology

A 65-year-old man undergoes a shave excision of a suspected skin tag on his upper back. Histology unexpectedly shows melanoma with a Breslow thickness of 0.6 mm. The deep margin is transected. What is the recommended next step?

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Correct answer: A — Re-excision of the scar with 1 cm margins

For a 0.6 mm melanoma (pT1a), BAD guidelines recommend wide local excision with 1 cm margins. The transected deep margin from the shave excision necessitates re-excision to ensure complete tumour removal and accurate staging. The excision should include the full scar and 1 cm peripheral margins down to the deep fascia. SLNB is generally not indicated for melanomas <0.8 mm unless adverse prognostic features (e.g., mitotic rate ≥2/mm², lymphovascular invasion) are present. Observation alone is not acceptable with a transected margin.

Reference: BAD 2017 Melanoma Excision Margin Guidelines