The most important part of treating a melanoma is to excise it from the skin. This is usually effected in two stages. First the suspicious lesion is excised. This is called an “excisional biopsy”. If melanoma is confirmed, a later larger excision is undertaken including a large margin of apparently normal skin around the site of the excisional biopsy. This is called a "definitive excision". Taking a rim of normal skin reduces the chance that the melanoma will later re-grow nearby. Once you have been diagnosed with a melanoma, you need follow up appointments for life. There are two main reasons for this:
to look for signs that it may have spread. Management may change if there is evidence of spread.
to check the skin for a possible second melanoma. A person who has had one melanoma on their skin has a 13% chance of growing a second melanoma in the next 10 years. This risk continues forever.
A melanoma is the most dangerous of the common skin cancers. Even small melanomas can spread through the body via blood and lymphatic vessels. The cancer can spread to organs such as the lymph glands, lungs, liver and brain. Indeed it can spread to almost any organ in the body. This is why melanoma is so dangerous. Once spread, it can invade and destroy the function in these organs leading to death in most cases.
Fortunately most cases of melanoma are caught before any spread has taken place. Removing the melanoma early with an adequate margin of surrounding skin is life saving; the earlier the better.
There are features of a melanoma that help us determine how dangerous it may be. The pathologist report indicates a number of features of the melanoma that help us determine the risk that an individual melanoma might spread.
The most important feature of a melanoma is the Breslow thickness. This is the depth in millimeters that the cancer has burrowed into the deeper skin layers. The thicker the Breslow, the greater the risk that the melanoma may have spread. You doctor will advise you of the Breslow of your melanoma and explain the risk that it may have spread. Sometimes the melanoma has spread before it is diagnosed. There might be little islands of melanoma in distant parts of the body. Often we don’t know about these islands until sometime later when they have grown and are causing symptoms in that organ. We don’t routinely scan parts of the body for the possibility that a melanoma has spread. Find out why here.
We also do not routinely perform the controversial sentinel lymph node procedure when patients are diagnosedwith melanoma. Find out why here.
There are various sub-types of melanoma. Find out more here.