Melanoma is unique among cancers in its ability to spread literally anywhere in the body, but it usually recurs in predictable patterns. The most common place for an initial recurrence of melanoma is in the lymph nodes that drain the region of the primary lesion.
For example, if a primary melanoma on the left shin spreads to lymph nodes, it will almost always spread first to the lymph nodes in the left groin. A primary lesion located on the middle of the back, however, may spread first to the lymph nodes in either of the armpits, to those in either the groin or collarbone region, or even to either side of the neck. When melanoma spreads to lymph nodes, it shows up as a hard lump or lumps that are usually not painful unless they become very large.
It is important to realize that not all swollen lymph nodes are cancerous. We all get swollen lymph nodes from time to time as a result of infectious or inflammatory processes that we may not even be aware of. People with a history of melanoma are no different. So, if you feel a lump you think is a swollen lymph node, don’t panic, but do have it evaluated by your doctor.
In other patients, the first sign of melanoma recurrence may be the appearance of a lump or lumps under the skin. These subcutaneous nodules may show up either within or near the wide local excision scar or farther away from this site. These are usually very easily seen and felt under the skin, although they are usually not painful. Often they are darkly pigmented (blue or black).
Less commonly, melanoma may spread directly to an internal organ or organs without first showing up in the lymph nodes or under the skin. When it spreads to organs, melanoma most commonly metastasizes to the lungs, liver, and brain, but it may spread anywhere. Melanoma may be present in the internal organs for months or even years before you have any symptoms, because cancer in these locations cannot be seen or felt and usually does not cause problems until the lesions are quite large.
Symptoms experienced by people with melanoma that has spread internally vary depending on the organs involved. For example, melanoma in the brain may cause headaches, numbness, weakness, sleepiness, dizziness, or a seizure; melanoma that has spread to the lungs or the heart may cause shortness of breath or cough; and melanoma that has metastasized to the liver or other abdominal organs may cause fatigue or abdominal pain. Other lesions may cause other problems.
We all experience many of these symptoms from time to time, of course. If they are caused by metastatic melanoma, however, they will persist. A headache that is relieved with Tylenol, that is gone in a day or two, or that is typical of a person’s usual headaches is almost certainly not the result of melanoma in the brain, nor is a fleeting pain in the abdomen likely to be metastatic melanoma in the liver. You should contact your doctor if you develop any symptom out of the ordinary that persists for more than a few days. Lasting symptoms of any sort may be a sign of some sort of trouble, but not necessarily melanoma.