Look up crown gall - a contagious condition caused by a soil borne bacteria - to see if there is any resemblance. If that seems to be it, tree needs to be removed and burnt. And no susceptible kinds of replacement trees can be depended upon to grow in the same spot without becoming infected. Also an effort should be made to not spread soil from the planting site on footwear and tools.

Thanks for the answer. She doesn't think the description quite fits. She said the area is woody and not spongy. But I did some reading too and I read that old galls can get a woody interior,

This reference seems quite relevant:

"Crown gall first appears as small overgrowths on the stem (trunk), crown, and roots – usually near the soil line, frequently at a graft union"

However, this reference in the same article seems to go in another direction:

"Since the crown gall bacterium infects only through wounds, the disease can be confused with the callus overgrowths that often form at wounds or graft unions."

full article: https://ipm.illinois.edu/diseases/rpds/1006.pdf

Is her pic beyond "callus overgrowths"?

It seems like the plant will eventually suffer if it is galls and as as they encircle the trunk. But yet its going strong for now so is there a reasonable argument to wait-and-see?

Reminds me of a medical tv drama I just watched where the surgeon needs to decide whether or not to remove the stomach of a patient because they can't determine if the growths are cancerous or not!

Might it just be a somewhat incompatible very low graft with the root stock outgrowing the desired variety?