What’s the name of this sign? What does it tell you?

What’s the name of this sign? What does it tell you?

A patient presents for routine screening, including a skin exam. What’s the name of this sign and what does it tell you. (Scroll below for the answer and more info.)

ugly duckling sign 2

Answer: The Ugly Duckling Sign

The ugly duckling sign refers to one mole among many that sticks out and looks different (“the ugly duck”) and should raise suspicion for melanoma.

We continue our dermatology series with the release of our newest Stanford 25 page: Approach to the Nevi (mole) Exam. Visit the page to learn more about the signs of melanoma and other normal findings you’ll see along the way.