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Melanoma skin cancer sign: Diameter

A mole, showing its width compared to a pencil eraser

Melanoma is the most serious type of skin cancer. The most important warning sign of melanoma is a change in the size, shape, or color of a mole or other skin growth, such as a birthmark.

  • A change in diameter (width) is one thing to watch for. Call your doctor if:
    • The width of a mole or skin growth is larger than 1/4 inch (6 mm), or about the size of a pencil eraser.
    • Any mole seems to be growing, even if it is still smaller than 1/4 inch (6 mm).

ByHealthwise Staff
Primary Medical Reviewer Kathleen Romito, MD - Family Medicine
Adam Husney, MD - Family Medicine
Specialist Medical Reviewer Amy McMichael, MD - Dermatology

Current as ofMay 3, 2017

Current as of: May 3, 2017

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine & Adam Husney, MD - Family Medicine & Amy McMichael, MD - Dermatology