Thank you for the tag
@Wendy&Neko
Our Roxi had adrenal-based Cushing's. We had a really good IM and surgical team work on her case. The problem, as they explained it to me, is that the tumors that cause adrenal-based Cushing's in cats are almost always malignant although they only spread locally. However, because the adrenal sits right next to both the caudal vena cava and the abdominal aorta, the tumor will grow around and into one of both of those blood vessels. So removal isn't recommended so much as required if you want to give her a good chance at survival. The meds that are used for pituitary-based Cushing's just won't work on the adrenal-based type, all concerns for tumor growth aside. And you will reach the point, as we did, where her glucose is not able to be controlled because the tumor will start to pulse production of cortisol on and off. So while it's producing cortisol, you'll need a really high dose...but it can then pulse off with no warning at all leaving you fighting super low hypo numbers for prolonged periods of time (days, not hours where you have to feed glucose every 20 minutes).
It is a fairly intense surgery though. I would want the same type of team that we had - a board-certified IM specialist plus a board-certified surgeon (a vet who specializes and has extra training specifically in surgery). In your case, I would also absolutely want a board-certified cardiologist on your team. It is significantly more expensive to go the specialist route, but her chances of making it through surgery and into a full recovery are also so much higher that way.
If you decide to go the surgical route, please let me know so I can give you more information.