Blueberry plants and crown galls
Thank you for your question. Is the third photo in the following resource what you are observing? https://pnwhandbooks.org/plantdisease/host-disease/blueberry-vaccinium-corymbosum-crown-gall Let us know.
It’s actually more like the 2nd photo on that link, however it is above the soil line at the base of the stem.
Then it is a crown gall.
That's what I was thinking but wanted to verify. Thank you!