What is melanoma?

Many of us have had loved ones affected by skin cancer. Some forms of skin cancer are more aggressive than others. Here's what you need to know about the most concerning type of skin cancer - melanoma.

Melanoma is a kind of cancer that begins in the pigmented producing cells of the skin called melanocytes. Melanoma usually starts as a dark spot on the skin. More rarely, it can originate in the eye or internal organs. Melanoma is the most serious and potentially aggressive type of skin cancer, but is treatable and curable when caught early. Each year there are over 200,000 cases reported and the trend continues to rise. Melanoma occurs when the pigment-producing cells that give color to the skin become cancerous. Symptoms might include a new, unusual growth or a change in an existing mole. Melanomas can occur anywhere on the body--even on the bottom of your foot. For most melanomas (depending on stage) surgical removal is curative.  If the melanoma has spread to the deeper layers of the skin, the dermatologist may refer to an oncologist for further evaluation including CT or PET scans and lymph node evaluation. If the cancer has spread, it may require further treatment with other treatments such as chemotherapy.


As you can see from the graph, the majority of patients affected are elderly, but it can affect younger individuals in the 20s and 30s as well.

Types of melanoma

Superficial spreading melanoma is the most common type. In women, the most common place for it to start is on the legs. In men it’s on the chest and the back. The melanoma cells usually grow slowly at first and spread out across the surface of the skin.

Nodular melanoma is the second most common type. It can grow more quickly than other melanomas and is usually found on the chest, back, head or neck.

Lentigo maligna melanoma is usually found in older people in areas of skin that have had a lot of sun exposure over many years. It’s often found on the face and neck. 

Acral melanoma is the rarest type and is usually found on the palms of the hands, soles of the feet, or under fingernails or toenails. It’s more common in people with black or brown skin and isn’t thought to be as related to sun exposure. 


Once the type of melanoma has been established, the next step is to classify the disease as to its degree of severity.

Classifications for melanomas are called stages. The stage refers to the thickness, depth of penetration, and the degree to which the melanoma has spread. The staging is used to determine treatment.

Stage I tumors have invaded the skin but are small, nonulcerated, and are growing at a slow mitotic rate. The five-year survival rate for stage 1a is 97 percent and 92 percent for stage 1b. The 10-year survival rates are 95 percent for stage 1a and 86 percent for Stage 1b, according to the American Cancer Society.

Stage II tumors, though localized, are larger (generally over 1 mm. thick) and/or may be ulcerated or have a mitotic rate of greater than than 1/mm2; they are considered intermediate melanomas. The five-year survival rate for stage 2a is 81 percent and 70 percent for stage 2b. The 10-year survival rates are 67 percent for stage 2a and 57 percent for stage 2b, according to the American Cancer Society.

Stages III and IV have spread (metastasized) to other parts of the body. There are also subdivisions within stages.  At this point, the tumor can be any size or shape. To be considered stage 3 melanoma, the cancer has to have spread to the lymph system. Surgery to remove cancerous tissue and lymph nodes is possible. Radiation therapy and treatment with other powerful medications are also common stage 3 treatments. TheAmerican Cancer Society reports the five-year survival rate for stage 3 melanoma ranges from 40 percent to 78 percent. The 10-year survival rate ranges from 24 percent  to 68 percent.

Stage 4 melanoma means the cancer has spread to other parts of the body, such as the lungs, brain, or other organs and tissue. It may have also spread to lymph nodes a good distance from the original tumor. Stage 4 melanoma is difficult to cure. The five-year survival rate is only about 15 percent to 20 percent. The 10-year survival rate is 10 percent to 15 percent, according to the American Cancer Society.


In its early stages, melanoma is a treatable condition. But, the cancer must be identified and treated swiftly. Annual visits to a dermatologist and self-checks can help you avoid melanomas and other types of skin cancers. If you ever see a new mole or a suspicious mark on your skin, have it evaluated by a dermatologist promptly. If your immune system is weakened by a condition such as an organ transplant or HIV, getting checked is especially important. 

What to look for:


If you or a loved one has a changing or new spot, make sure to have it checked out right away!