T.,
Long story short - yes, take the whole thing out. I too had a similar situation. 1/2 was taken out. Then after I was released from the hospital they said they found some cancer cells and had to go back in to take out the other 1/2.
I can't tell you how many people I've talked to that have had problems either with the other 1/2 or with trying to regulate their levels only having 1/2.
It's easier to regulate the hormone when you have NONE than if you have a sometimes functioning 1/2. I've heard tons of stories from people who have been all over the board with their levels because the partially functioning thyroid that's left just isn't consistent.
Do yourself a favor. Get rid of it now. Get a great endocrinologist and listen to your body. Don't take any chances that the part that's left in gets cancer or throws your whole body out of whack.
If you want to talk more, just e-mail me. I went through this back in 2000 and have been GREAT ever since changing Endos. Two healthy kids and a third on the way!
Sara