If it is cancer (which, if I've got this right, hyperparathyroidism is?) they'll want to do a bunch of ultrasounds and/or x-rays to look for tumors, but if we can be assured that we can keep her comfortable, we probably will not go any further in exploring. She turned ten on the day of her blood test, and I am reading (I know I said no more googling, but what can I say?) that she won't necessarily have symptoms to speak of until she's really getting ready to go. If I've got this right, she will basically experience what an old dog experiences- getting old and dying of natural causes. I think that's a better scenario than lots of time spent at the vet's office trying to find/treat something at her age.
So that's all the news that isn't, yet. I'll keep you posted. Thanks for asking, and for your good thoughts and wishes for Callie-loo! We're spoiling her in the meantime- a friend saw her last night and said "Callie's looking... healthy...." and he meant FAT. But she's loving life, still being the nearly-perfect pup that she is, and taking every chance she gets to roll in the snow/grass with delight. Lookit that face!!