Clonal naevi more common in children
Symmetrical lesions like this are rarely of concern, but because of the dark central area, naevi like this are often excised.
These are better described as combined naevi with two populations of naevus cells. Most lesions are on the face and sometimes have a rapid growth phase.
A common combination is a blue naevus surrounded by a common dermal nevus, or a Spitz naevus in the centre of a common naevus.
The term ‘clonal’ is probably incorrect in that the cells in each naevus subtype are not genetically identical, so ‘combined naevi’ is more accurate.