Surgery is the usual treatment for melanoma. The surgeon removes the tumor and some normal tissue around it. This procedure reduces the chance that cancer cells will be left in the area. The width and depth of surrounding skin that needs to be removed depends on the thickness of the melanoma and how deeply it has invaded the skin:
- The doctor may be able to completely remove a very thin melanoma during the biopsy. Further surgery may not be necessary.
- If the melanoma was not completely removed during the biopsy, the doctor takes out the remaining tumor. In most cases, additional surgery is performed to remove normal-looking tissue around the tumor (called the margin) to make sure all melanoma cells are removed. This is often necessary, even for thin melanomas.
- If the melanoma is thick, the doctor may need to remove a larger margin of tissue. If a large area of tissue is removed, the surgeon may do a skin graft. For this procedure, the doctor uses skin from another part of the body to replace the skin that was removed.
Lymph nodes near the tumor may be removed because cancer can spread through the lymphatic system. If the pathologist finds cancer cells in the lymph nodes, it may mean that the disease has also spread to other parts of the body. Two procedures are used to remove the lymph nodes:
- Sentinel lymph node biopsy—The sentinel lymph node biopsy is performed after the biopsy of the melanoma but before or in conjunction with the wider excision of the tumor. A radioactive substance and sometimes a blue dye is injected near the melanoma. The surgeon follows the movement of the substance radiographically and with a hand-held probe. The first lymph node(s) to take up the substance is called the sentinel lymph node(s). (The imaging study is called lymphoscintigraphy. The procedure to identify the sentinel node(s) is called sentinel lymph node mapping.) The surgeon removes the sentinel node(s) to check for cancer cells. If a sentinel node contains cancer cells, the surgeon removes the rest of the lymph nodes in the area. However, if a sentinel node does not contain cancer cells, no additional lymph nodes are removed.
- Lymph node dissection—The surgeon removes all the lymph nodes in the area of the melanoma. Therapy may be given after surgery to kill cancer cells that remain in the body. This treatment is called adjuvant therapy.
Surgery is generally not effective in controlling melanoma that has spread to other parts of the body. In such cases, doctors may use other methods of treatment, such as chemotherapy, biological therapy, radiation therapy, or a combination of these methods.