Melanoma is a type of cancer that begins in the melanocytes. These are cells that make the pigment melanin. Melanomas often start in moles on the skin. They can also start in other parts of the body that have melanocytes. This includes the fingernails, toenails, eyes, and the GI tract. Rarely, melanomas can also form in the nasal passages, sinuses, or in the genital area. Melanoma can spread (metastasize) to other parts of the body.

Risk Factors

Each year, doctors diagnose almost 100,000 new cases of melanoma in the United States. Your risk of a melanoma diagnosis goes up as you get older. But a diagnosis can occur at any age.

Known risk factors for melanoma include:

  • Fair Skin: Skin that burns or freckles easily puts you at higher risk. However, people with all skin types get melanoma.
  • Family History: Having a parent or siblings diagnosed with melanoma. Family history does not mean you will get cancer.
  • Moles: Having a lot of moles raises your risk.
  • Personal History: Having a melanoma increases your risk for a second melanoma.
  • Severe Sunburns: Having at least one severe sunburn as a child, teenager, or adult. Sun protective clothing can help reduce the risk of sunburns and melanoma.
  • Ultraviolet (UV) Radiation From the Sun: Where you live matters. Levels of UV radiation are higher in places close to the equator. They also increase at higher elevations. Sunlamps and tanning booths also use UV radiation, increasing the risk of melanoma.
  • Weakened Immune System: Certain drugs and diseases weaken the immune system and can increase the risk of melanoma.

Signs and Symptoms

A new mole that pops up might be a melanoma. So might an older mole that changes size, shape or color. Or, one that starts to feel different or begins to itch, ooze, or bleed.

The ABCDEs of Melanoma is a guide to finding moles that may be cancer. See your doctor or a dermatologist (a doctor who specializes in diseases of the skin) if you notice:

Asymmetry: One half of the mole looks different than the other half.

Border: The mole has a ragged, notched, or blurred edge or an uneven outline. Or, the coloring has started to spread into the skin around it.

Color: The mole has shades of black, brown, and tan. Or, it has areas that are white, grey, red, pink, or blue.

Diameter: The mole is growing in size. Melanomas are likely to be larger than the eraser of a pencil (1/4 inch or 5 millimeters).

Evolution: The mole is changing in size or in color over time.

Looking over your body once a month can help you spot new moles. It can also help you find moles that are changing. Taking photos of your moles can also help you track changes.


Diagnosis and Staging

Your doctor will look at your moles very closely. The doctor may even use special glasses. If a mole looks suspicious, your doctor will suggest a biopsy. This can be done two ways:

  • Excisional Biopsy: Your doctor will remove the entire mole and some of the skin around it. A pathologist will examine the tissue under a microscope to check for cancer cells.
  • Biopsy: Your doctor will remove a small piece of the mole. A pathologist will examine it under a microscope to check for cancer cells.

If cancer cells are found, you will be told you have melanoma. You will also learn how thick it is and how fast it is growing. Your doctor will use this information to stage the melanoma. It will also guide treatment options.

A cancer’s stage sums up how far the cancer has spread. Knowing the stage of the melanoma helps your doctors decide on the best treatment plan. There are five stages, Stage 0 through 4. The lower your stage, the less your melanoma has spread.


Cancer cells are only found in the outer layer of skin cells. They have not moved into deeper tissue.

The tumor is no more than 0.8 millimeters (about 1/30th of an inch) thick, without ulceration of the skin. (Ulceration can only be seen under a microscope.)

The tumor is no more than 0.8 millimeters (1/30th of an inch) thick, with ulceration of the skin. Or, the tumor is no more than 2.0 mm (1/25th of an inch in thickness) without ulceration.

The tumor is at least 1-2 millimeters thick with ulceration or between 2-4 mm thick without ulceration.

The tumor is 2-4 millimeters thick with ulceration. It also has an ulceration. Or, it is more than 4 mm thick without ulceration.

The tumor is more than 4 millimeters thick with ulceration.

Melanoma of any thickness where the cancer cells also have spread to one or more nearby lymph nodes. In some circumstances, Stage 3 melanoma can also occur when melanoma cells have spread to tissue near the main melanoma. These areas of cancer cells are called “satellites.”

The cancer cells have spread to other parts of the body including organs such as the bones, lungs, or liver.

Treatment and Side Effects

You and your cancer care team will work together to make treatment decisions. You will want to ask your team:

  • What is the type and stage of my melanoma?
  • What treatment do you recommend and why?
  • Am I eligible for a clinical trial?
  • How often will I receive treatment and for how long?
  • What is the plan if my disease progresses?
  • How often will I need to come in for follow-up care?
  • How will treatment affect my quality of life?
  • What types of side effects might I have?
  • What can I read to learn more about my treatment options?

Talk to Your Doctor About Clinical Trials

Your treatment options may include a clinical trial. Clinical trials are research studies with patients. Their goal is to find better ways to treat diseases like melanoma. Many people with melanoma get treatment in a clinical trial. Often, the most promising new approaches to treatment are only available through clinical trials.

Be sure to ask your doctor about clinical trials that may be right for you.


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