Awwwww Joan, unanswered questions are the worst, that's for sure.
What excuse is the vet giving you for not providing the ultrasound report? Although there really isn't any excuse for making you wait for a year!
If it gives you any comfort, though, it probably was a moot point as to whether there was actually an adrenal tumor present as opposed to the Cushing's being pituitary in origin. Trilostane is a recommended treatment for either form of the disease, and her cortisol level was being monitored via ACTH testing. So either way, probably nothing about her treatment would have changed. That's still no excuse for you not being able to find out the facts, but maybe it will give you some peace about the results -- no matter what they were.
Marianne