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Melanoma Risk Factors, Prevention and Diagnosis

Melanoma Risk Factors and Prevention

There are several risk factors for melanoma:

  • A previous cancer diagnosis, especially melanoma or another skin cancer such as basal or squamous cell
  • Family history of cancer, especially melanoma (5 to 10 percent of cases are genetic)
  • Excess exposure to sun and UV radiation
  • Multiple, blistering sunburns (about 20 percent of patients report a history of sunburns)
  • Cases of actinic keratosis, a rash of scaly or crusty bumps caused by the sun
  • Use of sun lamps and tanning beds
  • Fair complexion (though melanoma does occur in people with various skin tones and hair and eye colors)
  • Moles (including dysplastic nevi, or atypical moles), spots or lesions — areas with unusual growth or appearance
  • Immune system deficiency

You can potentially lower your risk by:

  • Staying out of direct sunlight between 10 a.m. and 4 p.m., when the rays are the strongest
  • Applying sunscreen with an SPF of 15 or higher and lip screen every day (reapply every two hours or after swimming)
  • Covering as much skin as possible, such as with a loose, long-sleeved shirt and long pants
  • Wearing a canvas hat with a wide brim when outside

Melanoma Symptoms

Have discussions with your doctor about skin cancer during your regularly scheduled appointments or if you notice any specific changes to your skin or to moles in particular. The most important changes to look for, and immediately discuss with your doctor, include changes in any mole including:

  • Growth, bleeding, or itching
  • Asymmetrical appearance (left and right sides of mole do not look identical)
  • Irregular, blurry, or jagged edges
  • Color change including loss, spreading, darkening, loss of color, or the appearance of multiple colors
  • Large size: a diameter greater than 6 mm (the size of a pencil eraser)
  • Raised above the skin with an uneven surface

You should also consult your doctor if you notice any lesions or areas of damaged skin. This includes lesions that:

  • Appear smooth or waxy
  • Grow in a cluster that is pink or red with a shiny or scaly appearance
  • Heal and reopen repeatedly
  • Form as a brown or black streak underneath a nail

Early detection can be your greatest tool in fighting skin cancer—treatment is much more effective when skin cancer is caught in its early stages.

Screening and Diagnosis

Melanoma is found anywhere on the body, including the trunk, arms and legs, head and neck and under the nails. It’s often identified by assessing the lesion or mole’s size, color, symmetry, border and changes. There are several tools for diagnosis, starting with a self-exam.


Spot changes to your skin and moles by doing a monthly skin self-exam, using a full-length mirror if possible.

  • Look at your sides with your arms raised.
  • Bend your elbows and look at your forearms and upper arms. Don’t forget to look at your hands.
  • Sit down to look at the front and back of your legs and feet. Remember to look between your toes and on the bottom of your feet.
  • Check the back of your neck and your scalp. Try using a handheld mirror for a better look.

Physician Screening

Have a dermatologist check you once a year for any skin growths that could potentially be skin cancer. You may also want to take note of any moles or large freckles you have, paying careful attention to their shape and size, and point them out to your dermatologist at your appointment.

At a screening for skin cancer, you can expect MedStar Health dermatologists or dermatologic oncologists to review your medical history, perform a physical exam, and even take photographs to monitor any suspicious lesions. Our specialists may need to perform one or both of the following procedures:

  • Dermatoscopy—The dermatoscope is a hand-held medical device that is composed of a series of lights or bulbs and a magnifying lens. Your physician can evaluate features of a mole using this device. Certain characteristics make a mole more likely or less likely to be melanoma—the dermatoscope allows doctors to examine the mole to determine if a biopsy is necessary.
  • Biopsy—If your physician has determined that the structure of the mole is not stable, meaning it needs to be examined more carefully under a microscope, you may need a biopsy. Biopsy techniques include
    • Shave biopsy—Performed with either a handheld blade or a DermaBlade. Neither of these requires stitches.
    • Punch biopsy—Removal of a core of tissue and requires a few stitches.
    • Excisional removal—If the mole is large, your physician will perform a narrow cut to remove the entire mole.

Any biopsies taken will be reviewed by a dermatopathologist for signs of cancer. If necessary, you may be evaluated by other specialists, including surgical oncologists.

If a biopsy indicates that you have malignant melanoma, your surgical oncologist will need to determine if the cancer has spread, either to your lymph nodes or to other areas of your body. Tests that show if the cancer has spread include:

  • Blood tests
  • Biopsies – Your surgical oncologist will use one of several biopsy methods to determine if the malignant melanoma is spreading to the lymph nodes near your affected area.
  • Chest x-ray – Using an x-ray, your surgical oncologist can determine whether the malignant melanoma is spreading to the lungs.

Some patients may be at risk for further complications, including spread of melanoma to the lymph nodes. For these patients, we also recommend the following imaging tests:

  • Computed tomography (CT or CAT) scan – This imaging test uses x-ray technology and computers to create a detailed picture of areas in your body where the malignant melanoma may have spread.
  • Magnetic resonance imaging (MRI) – This imaging test uses high powered magnets to create a picture of areas in your body that may be affected by malignant melanoma.
  • Positron emission tomography (PET) scan – This imaging test can identify the presence of cancerous cells in areas aside from your skin. Your doctor will inject a vein with radioactive glucose, and then follow it as it affects different types of cells. Cancerous cells absorb the glucose differently than non-cancerous cells.

Melanoma Staging

The results of your tests and biopsies will help your surgical oncologist describe your skin cancer. This description, also called staging, determines what kind of treatment will work best. Staging is based on:

  • The thickness of the melanoma, or how far down into the skin it is
  • Whether you have ulceration
  • How many abnormal melanoma cells appear under a microscope (mitotic rate)
  • Whether your melanoma has spread to lymph nodes or other organs. We will learn this from a sentinel lymph node biopsy.

Staging is a range that goes from Stage I to Stage IV. Stage I means your melanoma is only on the top of your skin and has not yet spread. On the other end of the spectrum is Stage IV, which means it has spread to your organs or lymph nodes.


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