Melanoma: Symptoms and Signs

Approved by the Cancer.Net Editorial Board, 09/2015

ON THIS PAGE: You will find out more about body changes and other things that can signal a problem that may need medical care. To see other pages, use the menu on the side of your screen.

ABCDE rule

Changes in the size, shape, color, or feel of a mole is often the first warning sign of melanoma. These changes can occur in an existing mole, or melanoma may appear as a new or abnormal-looking mole. The "ABCDE" rule is helpful in remembering the warning signs of melanoma:

  • Asymmetry. The shape of one half of the mole does not match the other.

  • Border. The edges are ragged, notched, uneven, or blurred.

  • Color. Shades of black, brown, and tan may be present. Areas of white, gray, red, or blue may also be seen.

  • Diameter. The diameter is usually larger than 6 mm (1/4 inch; the size of a pencil eraser) or has grown in size. Melanoma may be smaller when first detected.

  • Evolving. The mole has been changing in size, shape, color, or appearance, or growing in an area of previously normal skin. Also, when melanoma develops in an existing mole, the texture of the mole may change and become hard or lumpy. Although the skin may feel different and may itch, ooze, or bleed, melanoma usually does not cause pain.

When to see a doctor

Many melanomas are dark brown/black and are often described as changing, different, unusual, or “ugly looking.” However, any skin abnormality that is growing or changing quickly and does not go away, whether colored or not, should be examined by a doctor. Bleeding may be a sign of more advanced melanoma. In addition, the appearance of a new and unusual mole is more likely to be melanoma.

If you are concerned about a new or existing mole, please talk with your doctor. Your doctor will ask how long and how often you’ve been experiencing the symptom(s), in addition to other questions. This is to help find out the cause of the problem, called a diagnosis.

If melanoma is diagnosed, relieving symptoms remains an important part of cancer care and treatment. This may also be called symptom management, palliative care, or supportive care. Be sure to talk with your health care team about symptoms you experience, including any new symptoms or a change in symptoms.

The next section in this guide is Diagnosis, and it explains what tests may be needed to learn more about the cause of the symptoms. Or, use the menu on the side of your screen to choose another section to continue reading this guide.