Canadian Cancer Society logo


You are here: 

Surgery for melanoma

Surgery is the primary treatment for melanoma. Surgery is used to:

  • potentially cure the cancer by completely removing the tumour
  • remove lymph nodes
  • remove metastases to the brain, lung, liver, bowel, subcutaneous tissues or pancreas
  • reduce pain or ease symptoms (palliative treatment)

The type of surgery done depends mainly on the thickness or stage of the melanoma and other factors, such as location of the melanoma. Side effects of surgery depend on the type of surgical procedure.

Wide excision

Wide excision (surgical removal) of the tumour or biopsy site is the primary treatment for melanoma. Depending on the depth of the melanoma, wide excision also removes a 1–2 cm of normal-looking tissue all around the melanoma. The area of healthy tissue around the tumour is called the margin. The margin is removed to make sure that no melanoma cells were left behind after the biopsy. The recommended size of the margin varies depending on the thickness of the tumour and its location. The surgeon removes the subcutaneous tissue down to the level of the muscle, but does not remove muscle. If sentinel lymph node biopsy (SLNB) is being considered, it may need to be done before surgery because certain types of skin reconstruction flaps can affect the accuracy of the SLNB.

Surgical margins for excision of melanoma
Tumour thicknessRecommended surgical margins

in situ

0.5–1.0 cm margin plus a layer of subcutaneous tissue

1 mm or less

1 cm margin

1–2 mm

1–2 cm (when possible)

2–4 mm

2 cm

greater than 4 mm

2 cm

In some cases, melanomas on the face or vital structures may be removed with smaller margins.


For tumours on the fingers, toes or nails, amputation at the nearest joint is often suggested.

Sentinel lymph node biopsy (SLNB)

The sentinel lymph node is the first lymph node in a chain or cluster of lymph nodes that receives lymph fluid from the area around a tumour. Cancer cells will most likely spread to these lymph nodes first. Sentinel lymph node biopsy (SLNB) removes the sentinel lymph node(s) to see if it contains cancer. There may be more than one sentinel lymph node, depending on the drainage route of the lymph vessels around the tumour.

SLNB is a staging procedure that may be used to provide prognostic information for people with melanoma. It is most often used for people with melanoma that is thicker than 1 mm, but who do not have any clinical evidence that cancer has spread to the lymph nodes. For melanomas that are less than 1 mm thick, it is unknown whether there is benefit of SLNB for prognosis. It is not known if there is any increased survival benefit after SLNB.

SLNB is not used for people:

  • with melanoma in situ
  • with stage 1A melanoma
  • with lymph nodes that the doctor can feel
  • who have already had surgery on a lymph node
  • with locally advanced melanoma that has spread to the lymph nodes
  • with metastatic melanoma

SLNB should be done at the same time as wide local excision. It can be done after wide local excision, in certain cases, but it is preferable to do it at the same time as wide local excision.

If the results of the SLNB are negative (no cancer cells are present), then it is unlikely that other lymph nodes are affected and no additional surgery is necessary. If the results of the SLNB are positive (cancer cells are present), all of the lymph nodes in the area may be removed or the person with melanoma may be offered the chance to participate in a clinical trial.

Lymph node removal

Lymph node dissection or removal involves surgery to remove the lymph nodes in the area near a tumour. The lymph nodes in the area will be removed if results of the biopsy show that the cancer has spread to the lymph nodes or if SLNB was positive.

Surgery to remove the lymph nodes damages the normal draining pathways for lymph fluid and can cause a buildup of fluid called lymphedema. This is an uncomfortable side effect and may last a long time. Therefore, complete removal of the lymph nodes is only done when necessary to treat the person.

Depending on the location of the tumour, different lymph nodes will be removed:

  • axillary lymph nodes (in the armpit)
  • inguinal and iliac lymph nodes (in the groin)
  • cervical lymph nodes (in the neck)

If a melanoma is thicker than 4 mm, there is a higher risk that the cancer will spread.

Any lymph nodes that can be felt on physical examination (are palpable) are usually removed by surgery after they are biopsied and there is proof that they are enlarged because of melanoma metastasis.

Surgery to remove a metastasis

If there is only a single metastasis in the brain, liver, lung, bowel, subcutaneous tissue or pancreas, and no metastasis anywhere else in the body, it may be possible to remove it with surgery. This type of surgery would be carried out in a specialized centre. For example, removal of a single brain metastasis would be performed by a neurosurgeon (brain surgeon).


Reconstructive surgery helps to restore the structure and appearance of the body. A skin graft or skin flap may be used to repair damage caused by the excision of melanomas that cover a large area. They may also be used to cover wounds if there is not enough skin for the wound to close.

See a list of questions to ask your doctor about surgery.


Dr John Dick A new understanding of blood cells

Read more

Providing rides to cancer treatment

Illustration of car

For more than 50 years, the Canadian Cancer Society’s transportation program has enabled patients to focus their energy on fighting cancer and not on worrying about how they will get to treatment.

Learn more