Dermatofibroma is a benign (non-cancerous) growth that typically appears as a small, firm bump on the skin. They are usually brown or red in colour and can appear anywhere on the body but are most commonly found on the legs.
They are caused by an accumulation of fibrous tissue and are not usually harmful or painful, but some people may choose to have them removed for cosmetic reasons. DFs are thought to be caused by trauma to the skin such as an insect bite, hence why more common on limbs. Interestingly, they are not seen on the face very often. DFs should not grow much therefore, if you find your DF to be increasing in size it should be reviewed.