Ella went to the vet for a bald spot on her side (which is so typical of Ella's skin issues) because it wouldn't drain. Nothing was coming out of it.
She was diagnosed with a mast cell tumor last Tuesday. They did pre-op blood work and she's going in for surgery tomorrow. We most likely caught it early, so it will most likely be benign/stage I.
Here's a pic, it's the bald spot on her side here:

She's young, strong, and otherwise extremely healthy. The vet doesn't believe it's internalized/effecting anything on the inside because she's not showing any symptoms of that. I'm thinking that once this is removed, it'll never come back again.
Yes, I'm going to be requesting pre-op benadryl. Some vets think it's necessary, others don't. But I'm going to request it as it cannot hurt. I don't want to dose her myself since she cannot eat anything before surgery.