Surgical excision is the mainstay treatment for melanoma. Surgical margins and indication for lymph node evalution are determined by the thickness of the primary mleanoma. Accurate diagnosis of nodal status has significant prognostic implications. Positive nodal metastasis is associated with decreased survival. As the thickness of the primary increases, incidence of nodal metastasis also increases. In the future gene expression profiling may play an important role in risk stratification of the patients and possibility of nodal disease.
- 0-0.75mm thick = near zero
- 0.75 – 1.49mm thick = up to 25%
- 1.5 mm – 3.9mm = up to 60%
- >4mm = 65%+
| Depth of primary Melanoma | Surgical Margin |
|---|---|
| MIS | 5 mm |
| <1mm | 1 cm |
| 1-2mm | 1-2 cm |
| 2-4mm | 2 cm |
| >4mm | 2 cm or more |
|
Depth of invasion |
Ulceration |
Margin |
SLN |
|
In situ tumor |
N/A |
5 mm |
No |
|
No |
1 cm |
No |
|
|
Yes |
1cm |
maybe** |
|
|
1-4 mm |
Yes/No |
2 cm |
Yes |
|
>4 mm |
Yes/No |
Min 2 cm |
Offer |
**Some data suggest patients with melanoma less than 1mm and certain aggressive features may benefit from SLNB: young age, ≥Clark's IV, ulceration, regression, incomplete biopsy, high mitotic rate