This is a type of fibrous or scarring reaction that occurs in the second layer of the skin. It has a very characteristic appearance and can usually be diagnosed simply without needing to be excised. They never turn into skin cancers.
The only possible treatment is by surgery which leaves a scar so they are usually best left alone. The cause of these spots is unclear but they often seem to appear after a minor injury to the skin such as a prick from a thorn or an insect bite. Certain patient groups can be more prone to developing dermatofibromas.
Useful websites
http://www.bad.org.uk/for-the-public/patient-information-leaflets
