Hi Anne
Are you saying the tumor is not gone?
Is it possible because of all the surgery and the area of the surgery, that the sciatic nerve is acting up? This can cause very bad pain from the butt area, all the way down the thigh. PT can help it though. With 3 small children I'm sure plenty of strain is put on your back during the day.
Are you dealing with army doctors solely or private doctors also. Not that it would make a difference. but with a rare benign tomor such as you had, I'd think private doctors would have more info and experience with that sort of thing.
For now, I would simply get examined and see what can be done to help the pain get better, and find out for certain what is causing the pain.
Sorry I have no experience with the dermoid tumors, just hate seeing a post go unanswered.