Shell rot??

[jonckt]

 

[jonckt]

View attachment 132597

 

[Killerrookie]

Your tortoise looks fine to me but then again I don't own a radiated tort.

 

[jonckt]

Scrubbed it off and it leaves some hole in it.

 

[Killerrookie]

I've personally never seen this before. Wait till a expert comes in that knows about this.