Procedure
By Mia Wangsmo Steffenssen MD, Mike Mikkelsen Lorenzen, MD and Pia Sjøgren MD
Primary excision
Suspicion outside the plastic surgery specialty: Should refer the patient to the Department of Plastic Surgery.
At the Department of Plastic Surgery: the element should be excised with a 3-5 mm distance. Whenever possible, an excision margin of 5 mm should be chosen, as this serves as radical treatment of benign lesions as well as in situ melanoma.
Lower margins of excision biopsy can be chosen due to cosmetic or reconstructive purposes.
Step 1: Preoperative drawing
The pigmented lesion is marked with a 5 mm excision margin
Step 2: Excision
The element is excised in a circular fashion with a macroscopic layer of subcutaneous fat
Step 3: Closure
The defect is closed in two layers using a combination of a deep buried and cutaneous suture.
Reexcision
If the pathohistology shows malignant melanoma there is an indication for re-excision. The distance starts from the suture punctures and not the scar.
If the tumor depth is under 1 mm, the re-excision is 5 mm to muscle fascia. (Total distance 10 mm).
If the tumor depth is over 1 mm or if it is not possible to measure tumor depth, re-excision is 15 mm to muscle fascia. (Total distance 20 mm)
| Final distance of excision is always defined by tumour depth |
| MM in situ: total excision distance 5 mm MM ≤ 1 mm: total excision distance 10 mm MM ≥ 1 mm: total excision distance 20 mm |
If the melanoma was removed by a doctor outside the specialty of plastic surgery, the primary excision distance is unknown. Therefore the primary excision is 0 mm.
E.g: primary excision of SSMM 0.5 mm at general practitioner: 0 mm + 10 mm = Total distance 10 mm.
Re-excision procedure
Pictures missing
Sentinel node
Indications
Tumor depth is ≥ 0.8 mm (if 0.75 mm, round up to nearest decimal = 0.8 mm).
Tumor depth is not possible to measure.
The uncertainty of primary tumor or metastasis (and no distant metastasis on PET-CT).
Sentinel node and pregnancy
Sentinel node and scintigraphy is possible also for pregnant women. If the site of injection is close to the uterus (< 10 cm), the quantity of activity should be reduced, with a short interval to surgery. Methylene blue should not be used.
Contraindications
It is unnecessary when a patient presents with systemic disease. Similarly when a patient presents with a clinically evident node.
For patients who have previously undergone sentinel node, there is nothing in the literature to establish definitive recommendations.
Sentinel node procedure
The sentinel node is indicated by the scintigraphy. The typical localization for the sentinel node is for;
Extremities: toward node basins either in the axilla or groin.
Truncal region: can go to multiple nodal basins (axilla or groin).
Head and neck: follows the seven levels of head and neck
Sentinel node procedure from the groin
The sentinel node area (right groin) is identified at the scintigraphy. A search is then first conducted in the groin area. When the probe alerts the sentinel node, a marking is made.
Afterward, a small incision is made, and the sentinel node is removed. After removing the node, the probe is used to confirm. Then the probe is used to search for the remaining radioactivity in the area. The maximum remaining radioactivity accepted is 1/10 of the sentinel node (e.g. SN = 800, remaining activity of 80 is accepted).
Step 1: Prior to incision
Radioactive agent is traced percutaneously prior to the incision. The incision is marked by pen.
Step 2: Incision
A conservative incision is performed. Dissection continues until division of the fascia.
Step 3: Radioactive tracing
After division of the fascia the sentinel nodes are sought out assisted by the radioactive agent and patent blue colouring of the lymph vessels.
- Excise a suspect element for melanoma in a circular form, following a 3-5 mm distance around the element. If the element is removed in an eclipse form, unnecessary skin is removed. This could make the direct suturing of the re-excision difficult or impossible.
- If the defect is not possible to close primarily, it should be let open until diagnosis by pathology. Never undermine a defect after melanoma suspicion.
- If a defect is let open in the primary excision, evaluate if the re-excision will be under local or general anesthesia. Also, consider if skin transplant or a flap is needed.
- Local anesthesia should be infiltrated outside of the drawing in 3-5 mm distance of the element. Risk of spreading cancer cells.
- Never use curettage to remove a suspect element for melanoma. There is a risk of losing the possibility to measure dept at the pathohistological examination.
- Avoid incision biopsy of a part of an element suspected of melanoma. Risk of losing the possibility to measure depth.
