Skin cancer, melanoma

Other names: Melanoma


Melanoma, the most serious type of skin cancer, develops in the cells (melanocytes) that produce melanin — the pigment that gives your skin its color. Melanoma can also form in your eyes and, rarely, in internal organs, such as your intestines. The exact cause of all melanomas isn't clear, but exposure to ultraviolet (UV) radiation from sunlight or tanning lamps and beds increases your risk of developing melanoma.


Melanomas can develop anywhere on your body. They most often develop in areas that have had exposure to the sun, such as your back, legs, arms, and face. Melanomas can also occur in areas that don't receive much sun exposure, such as the soles of your feet, palms of your hands, and fingernail beds. The first signs often include a change in an existing mole or the development of a new pigmented or unusual-looking growth on your skin.

Normal Moles Normal moles are generally a uniform color with a distinct border separating the mole from your surrounding skin. They're oval or round and usually smaller than 1/4 inch in diameter.

Unusual Moles that may indicate Melanoma To help identify characteristics of unusual moles that may indicate melanomas or other skin cancers, think of the letters ABCDE: Asymmetrical shape, irregular border, changes in color, diameter larger than 1/4 inch, and evolving characteristics over time.

Hidden Melanomas Melanomas can also develop in areas with little sun exposure like under a nail or in mucous membranes. It's important to be aware of these hidden melanomas for early detection.

When to see a doctor Make an appointment with your doctor if you notice any skin changes that seem unusual.


Melanoma occurs when something goes awry in the melanin-producing cells that give color to your skin. Exposure to UV radiation is a leading cause of melanoma.


Factors that may increase your risk of melanoma include fair skin, history of sunburns, excessive UV light exposure, having many moles or unusual moles, family history of melanoma, and a weakened immune system.


Be well-prepared for your appointment by being aware of any pre-appointment restrictions, writing down symptoms and medications you're taking, bringing a family member or friend along for support, and preparing a list of questions for your doctor.


  1. What are some common symptoms of melanoma?

Change in an existing mole

Development of a new pigmented or unusual-looking growth on the skin

  1. What are some characteristics of unusual moles that may indicate melanoma?

Asymmetrical shape

Irregular border

Changes in color

Diameter larger than 1/4 inch

Evolving characteristics over time

  1. Where can hidden melanomas develop?

Under a nail

In mucous membranes

  1. When should you see a doctor regarding skin changes?

If any changes seem unusual

  1. What factors may increase the risk of developing melanoma?

Fair skin

History of sunburns

Excessive UV light exposure

Having many moles or unusual moles

Family history of melanoma

Weakened immune system

  1. How can you prepare for a doctor's appointment regarding suspected melanoma?

Be aware of any pre-appointment restrictions

Write down symptoms and medications

Bring a family member or friend along

Prepare a list of questions for the doctor

  1. How is melanoma diagnosed?

Through a biopsy procedure

  1. What are some treatment options for early-stage melanomas?

Surgery to remove the melanoma

  1. What treatments may be used for melanomas that have spread beyond the skin?

Surgery to remove affected lymph nodes


Radiation therapy

Biological therapy

Targeted therapy

  1. How can you reduce the risk of developing melanoma?

Avoiding sun exposure during peak hours

Wearing sunscreen year-round

Wearing protective clothing

Avoiding tanning lamps and beds

Regularly checking for changes in moles and skin growths