Can't see it real good, it's kinda dark.
What I "can see" is what looks like an injury of some sort. Dab some raw honey on it and, keep it under close observation. If it gets worse, take him/her to a "qualified" herp vet, not a regular vet. Most regular vets don't know squat about dragons.
How long is awhile? Would you say a few days, a few weeks, or months?
It does look like it possibly could have been a cut. Hopefully it's not some sort of growth though. When you feel it do you feel anything like a cyst underneath it?
I'd say a few months. At first he was shedding so I thought it was just apart of his shed, but over time it never went away. It doesn't seem to bother him, and it's not spreading or anything. It's just hard and scaley. I also couldn't find anything on it until I found this website and decided to make an account.