L.P.
I'm sorry your family is going through this. I don't have any experience here (sorry) but I was wondering, have you considered getting a second opinion 1st?
It does seem that the doctor isn't especially good at communicating- he may be a fine doc, however. You could call his office and leave a message to call you when he has time to answer some questions- if you do, keep a list by the phone so you don't forget anything.
I prefer doctors who take the time to communicate what is going on so we don't freak out. I know they're busy- but I'd say it's pretty important, and it's part of their job. I've switched docs more than once because of communication issues- and have never been sorry.
I know it's easier said than done, but try not to panic. It could very well all turn out to be nothing.
Hang in there! :)