Mass under our beagle's skin

[Munkos]

I found a hard, fixed lump under the skin on Coda's rear left leg today. It's about the size of half a small grape and not moveable. The skin moves over it, it seems attached to the tissues under neath. It's just above her knee joint. Our old guy had many lumps and bumps as he aged that we had aspirated, that never turned out to be anything significant. This doesn't resemble any of them

She'll be 7 in March and I just said to my DF the other day that she's seemed a little melancholy lately and that we should get her in for a senior wellness check soon. She's kind of been our 'problem' child since day one (BYB puppy) with health problems, allergies, etc. She's been a very expensive girl to keep up with, to say the least! So my gut kind of tells me we're in for another round of something not so easy. I really, really hope I'm wrong.

I don't know too much about lumps or our options (outside of aspirating them). We'll be taking her to the vet next weekend - if aspirating shows we need to do something more what's the best route to go? Complete removal? Biopsy? Can all lumps be aspirated or does it depend on the consistency?

Sigh. I hope it turns out to be nothing major!