Oh Dawn, Those lumps are so scary, and it's great that you are pursuing getting it checked out with a needle biopsy. Lumps or lipomas are
very common in middle age and older dogs. They are fat cell growths that can become huge over time. Usually they are found on the belly, and are movable below the skin. Years ago, my very old (now deceased, but not from the lipoma) Irish Terrier had one removed, after it got too big. His other lipomas were just left alone after the biopsy. My sweet ol' Yorkie, Lucy, just had one removed last spring because it was located right between her shoulder blades and was uncomfortable when she walked. We also left a small lipoma alone on an elderly foster I had, after it was biopsied. Even though I now know lipomas are common and not cancerous, I am still worry every time one crops up on one of my babies. I just wanted to share my experiences to help ease your mind that yes, biopsies (fine needle aspirations) of these nasty lumps can, and most often do, have a wonderful outcome.
Still, I will say a prayer for your sweet Miah (and you) during this scary time.
Veterinary Q & A - Lipomas (fatty tumors) in Dogs and Cats