I have lumps in my legs, mostly on left side. They are spasticity as far as I know. My pcp's PA showed me exercises to stretch them. If I don't do it, they keep me awake, but the exercises and self massage helps. Of course yours may not be the same cause. they are in quads as well as in calf muscle. I have also had to increase magnesium.

You referred to MGUS, the precursor of Myeloma. I have that too. My pcp who is in her 30's has that. Apparently people have it for very long times, usually, without it necessarily becoming Myeloma.