Dani, I'm no expert but it sounds to me as though infection is the most likely cause. Infection in or near exposed bone sounds like it would be quite serious, though, if she had radiation in that area.

I didn't know about altitude aggravating lymphedema. In a couple of weeks,I am flying on a business trip--a fairly long flight for the first time since my surgery and treatment. I have lymphedema at the base of my tongue--I hope that doesn't make it much worse.

I hope your mother's swelling is something temporary that goes away soon.

Nelie