I need to remove a stubbornly attached round ceiling medallion, 27" in diameter, that was above a chandelier on a drywall ceiling. It appears to be made of a sturdy lightweight material like plaster or hard foam. I would have assumed it was attached with adhesive, and it may partly be, but I'm pretty sure I have felt some inaccessible metal nails or screws when trying to pry a spatula up under it.

My concern is that I am going to severely damage the drywall ceiling if I pull this down. It's a visible area in the center of the dining room and the ceiling has a very small/fine texture.

 

Welcome to the forums!

Even if an adhesive was used, it would almost certainly have had a few nails or screws to hold it in place while the adhesive dried. When you remove the medallion you'll more than likely have to do some repair to the ceiling although if no adhesive was used the damage should be slight. Carefully inspect the face of the medallion and you should be able to spot the nails/screws - they will have been covered with putty.

 

You were correct, it did have about 15 or so nails as well as some adhesive. The nails were very thin and they had done a good job of puttying the holes to the point they weren't even noticeable. I went about halfway around the edge hammering a putty knife in until I was able to grip the medallion enough to pry it down, then it came down surprisingly easily. It slid right out of the nail holes in the ceiling with the nails still lodged in the medallion. Unfortunately, the adhesive did do some minor damage to the ceiling like you said, but only to the surface layer of the drywall.

Now on to my next project of patching that with no flashing...