Talk to Dermatologist on Pimple Like Growth For More Than Year

This dark pimple like growth is on my wife’s thigh. As far as memory recalls, this started as a bump with slightly reddish texture and it was thought to be a pimple that would go away with time. However it has been more than a year and it has stayed on, and dried into this enlarged black bump. Please advise if it can it be healed via meds or does it represent a more serious medical condition?