What Causes Dark Paining Bruise Like Spot In Ankle Area?

Hi, I have a dark spot in the ankle area. I noticed it about 6 month ago, and it seamed like a bite.
It seamed like it went away after a while, but I still had a dark spot in the size of the quater.
I forgot about It, since it didn't really bothered me, but recently noticed that I still have it. I also noticed that when I touch it it feels like a dent, and actually seams slightly bigger in size. Basically, it seams like a pale bruise and when I touch it I have a little pain, sort of like a bruise that is going away + it denty, and feels like it goes deeper in tto the tissue