Can't say exactly as I know, but I would be concerned it might be some kind of infection.
It seems odd they are kind of uniform in location, and growth.
If GC get cloudy it is usually a water quality issue. This isn't cloudy but you might try checking your water, or doing decent pwc? Poor water quality can cause injury to internal organs.
A parasite could be developing...
Is this a fish you have had for a long time?
Have you added any new fish recently?
Recent addition?
Do you have other GC's?