Melanoma is a type of skin cancer. It is the less common form of skin cancer but it can be more serious because it is more likely to spread to other parts of the body. Melanoma arises from the type of cells that give moles their dark colors. These cells can be found in the skin, eyes, digestive system, nail beds, or lymph nodes. Although melanoma is most common in the skin it may also arise in these other areas.


Cancer occurs when cells in the body divide without control or order. Eventually these uncontrolled cells form a growth or tumor. The term cancer refers to malignant growths. These growths invade nearby tissues and spread to other parts of the body. It is not clear exactly what causes these problems in the cells but is probably a combination of genetics and environment.


The most common risk factor for melanoma is exposure to ultraviolet radiation. The most common source of this radiation comes form the sun but it is also found in sun lamps and tanning booths.

Melanoma is found most often in older adults but it can happen in young adults. Other factors that increase the risk of melanoma include:

  • Certain types of moles called dysplastic nevi, or atypical moles
  • Large nevi present at birth
  • Fair skin, freckling
  • Red or blonde hair
  • Light-colored eyes
  • Caucasian race
  • Family members with melanoma
  • Excessive skin exposure to the sun without protective clothing or sunscreen
  • Suppressed immune system


Melanomas are not usually painful. They often have no symptoms at first.

The first sign is often a change in the size, shape, color, or feel of an existing mole. Melanoma may also appear as a new, dark, discolored, or abnormal mole. Remember that most people have moles. Almost all moles are benign.

The following are signs that a mole may be a melanoma:

  • Uneven shape
  • Ragged edges
  • Uneven color
  • Change
  • Large size

(See image on the right side below which shows an irregular border compared to the image on the left which is round with an even border.)

skin cancer identifying moles
Sign of Potential Melanoma  Copyright © Nucleus Medical Media, Inc.


Your doctor will look at your skin and moles. A sample of area will be removed and sent to a lab for closer examination. Your doctor may also examine lymph nodes. Enlarged lymph nodes may suggest the spread of melanoma. A sample of lymph node tissue may also be removed for testing.


Treatment options may include one or more of the following:

  • Immunotherapy
  • Surgery
  • Chemotherapy
  • Radiation Therapy

Melanoma Prevention

To reduce your chance of getting melanoma:

  • Avoid spending too much time in the sun
  • Protect your skin from the sun:
    • Wear a shirt, wide-brim hat, and sunglasses
    • Use sunscreens with a sun protection factor (SPF) of at least 15
    • Avoid exposure from:
      • 10 a.m. and 2 p.m. (standard time)
      • 11 a.m. and 3 p.m. (daylight savings time)
  • Avoid sun lamps and tanning booths

Early diagnosis and treatment is important. Take the following steps to find melanoma in its early stages:

  • If you have many moles or a family history of melanoma, have your skin checked regularly for changes in moles.
  • Ask your doctor to show you how to do a skin self-exam. Do self-exams to look for any new or changing moles.

Content was created using EBSCO’s Health Library. Edits to original content made by Rector and Visitors of the University of Virginia. This information is not a substitute for professional medical advice.