Is this a truffle?
This is out of my area of expertise. I do know the largest truffles ever found are about 3-4 lbs and smaller than the growths shown. I am sending your question and photos on to our lab people at OSU.
Difficult to tell from the images what this might be. The structures look woody rather than fleshy. It could still be fungal but does not seem like a truffles we know about. It looks more like a bacterial gall called crown gall. These are composed of disorganized parenchyma cells and do not have any vascular organization. It is not clear how these were found or what attachment they had to a tree?