Not normal.
There are a couple of pests/diseases that can affect quince roots.
Root knot nematode causes swelling on roots.
Crown gall is another.
I can't tell from the photos if it is one of these or something else but you have a couple of names to research.
Super common with the Chaenomeles speciosa apparently. As Shibui mentioned, I've heard it's a nematode that causes it.
Supposedly repotting in the fall instead of spring can limit the spread/formation of the growths.
Yep, these are regular issues. Some kind of response to bacteria or nematodes. I don't worry about them but that's just because I'd like these growths to become woody over time.