Hi. I've Had A Dent In My Thigh For Quite

Hi. I've had a dent in my thigh for quite some time now. I thougt it would just disappear after some time, because it appeared out of nowhere. It doesn't hurt or anything. I've tried massaging it, but without any succes. It feels like something is missing in that part or something like that. Should I be concerned and what must I do to get rid of it?