Recommended Surgical Margins for Melanoma with Depth > 2 mm

For melanomas with a depth greater than 2 mm, a surgical margin of 2 cm is recommended as the standard of care. 1

Evidence-Based Margin Recommendations

The recommended surgical margins for melanoma are based on tumor thickness (Breslow depth):

For melanomas > 2 mm thick (T3-T4), a 2 cm margin is the standard recommendation 1
This recommendation is supported by high-quality randomized controlled trials 1

The 2 cm margin recommendation for melanomas > 2 mm is based on several key findings:

The Intergroup Melanoma Trial compared 2 cm vs. 4 cm margins for melanomas 1-4 mm thick and found no difference in either local recurrence or survival rates 1
A European multicenter RCT involving 936 patients with melanomas > 2.0 mm thick compared 2 cm vs. 4 cm margins and found identical 5-year overall survival rates (65%) in both groups 1
Wider margins (> 2 cm) do not improve patient outcomes but do increase surgical complications and worsen cosmetic results 1

A narrower 1 cm margin for melanomas > 2 mm has been associated with higher recurrence rates:
- One RCT found that 1 cm margins for melanomas ≥ 2 mm were associated with higher combined local, in-transit, and nodal recurrence compared to 3 cm margins 1
- Long-term follow-up data from another trial showed that 1 cm margins were associated with significantly more melanoma-specific deaths compared to 3 cm margins for melanomas > 2 mm thick 2
Location-specific considerations:
- Most RCTs have excluded head and neck or acral sites, where functional and cosmetic concerns may necessitate narrower margins 1
- For trunk and extremity melanomas > 2 mm, the 2 cm margin is well-established 1

Using margins < 1 cm for invasive melanoma of any thickness is not recommended and increases local recurrence risk 1
Assuming that wider margins (> 2 cm) will improve survival - evidence shows no benefit but increased morbidity 1
Failing to consider the timing of sentinel lymph node biopsy (SLNB) - when planned, SLNB should ideally be performed before or during the wide excision to optimize lymphatic mapping 1

B. 1-2 cm is incorrect. While 1-2 cm margins are appropriate for melanomas 1-2 mm thick, they are insufficient for melanomas > 2 mm.

C. 2-4 cm is the correct answer. Specifically, a 2 cm margin is recommended as standard, with no evidence supporting margins > 2 cm.

A. < 0.5 cm is incorrect and dangerously inadequate for invasive melanoma of any thickness.

D. > 4 cm is incorrect and would cause unnecessary morbidity without improving outcomes.