Melanoma: Symptoms & Signs

Medically Reviewed on 9/10/2019

Melanoma is a type of skin cancer that forms in pigment-forming cells (melanocytes). (A mole, or melanocytic nevus, is a benign tumor of these pigment-forming cells.) Melanoma is the most serious type of skin cancer. Rarely, melanomas can be found in other areas of the body that contain pigment-forming cells, including the eye, the tissues around the brain and spinal cord, or the digestive tract. Melanomas of the skin produce changes in the appearance of the skin, but these changes can sometimes be seen with other skin conditions. The characteristic symptoms include a change in an existing mole or new mole with asymmetric borders, uneven coloring, increasing size, scaling, or itching. Melanomas are typically not painful. It is always important to seek medical advice when you develop a new pigmented spot on the skin or have a mole that is growing or changing.

Causes of melanoma

The cause of melanoma is not well understood. However, there are certain risk factors that increase your likelihood of getting melanoma. These include having atypical or dysplastic moles, having a large number of moles, having fair skin and light eyes, and having a personal or family history of melanoma. A history of blistering sunburns as a child or teen is another risk factor for melanoma.

Other melanoma symptoms and signs

  • Black Spot or Blue Spot on Skin
  • Bleeding Mole
  • Bump or Lump (Nodule) on Skin
  • Changing Appearance of Mole
  • Enlarging Mole
  • Itching Mole
  • Mole That Changes Appearance
  • Mole With a Large Diameter
  • Mole With Asymmetrical Shape
  • Mole With Changing Texture
  • Mole With Several Colors or Color Different Than Other Moles
  • Mole With Uneven or Irregular Borders
  • Oozing Mole
  • Redness at the Border of a Mole
  • Scaling Mole
  • Sore That Does Not Heal
  • Spot on Skin
  • Swelling Around the Edge of a Mole


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Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.