DermNet provides Google Translate, a free machine translation service. Note that this may not provide an exact translation in all languages
Home » Topics A–Z » Concentric circles dermoscopy
Author: Naomi Ashman, Dermoscopist, Torbay Skin, Auckland, New Zealand; DermNet New Zealand Editor in Chief Adjunct A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand. Created January 2019.
Concentric circles are a specific clue to melanoma on the face (lentigo maligna), but the clue has poor sensitivity as they are rarely present. In a study by Tschandl et al, concentric circles were only found in 4.2% of flat facial melanomas, usually larger lesions [1]. Concentric circles are also referred to as a circle within a circle and the isobar sign.
Concentric circles consist of an asymmetrical pigmented follicular opening with a darker dot located within ostial openings.
Concentric circles seen in dermoscopy of a lentigo maligna. Courtesy of Prof Cliff Rosendahl Concentric circles seen in dermoscopy of a lentigo maligna on the ear Concentric circles seen in dermoscopy of lentigo maligna on the face Concentric circles seen in dermoscopy of lentigo maligna on the ear Concentric circles seen in dermoscopy of pigmented actinic keratosis Concentric circles seen in dermoscopy of a pigmented actinic keratosis on the scalp
See smartphone apps to check your skin.
[Sponsored content]
Books about skin diseases
© 2021 DermNet New Zealand Trust.
DermNet NZ does not provide an online consultation service. If you have any concerns with your skin or its treatment, see a dermatologist for advice.