Thanks for writing to us
Nothing to worry about (unless there is pain).
One possibility is damage to the fatty layer. Do you recall a while back ever bumping your thigh, or having a bruise
in that area for any reason?
you need to meet with a plastic surgeon so he or she can examine you and feel the dent his or herself. If this depression
is an area of little or no subcutaneous fat, fat grafting might be an option.
I do hope that you have found something helpful and I will be glad to answer any further query.