Thanks for posting,
is not dangerous as it is a benign tumor
. Now depending on its size and presence of pain, a doctor could decide to excise and remove it, then send to a histologically laboratory for analysis. If is has increased in size ago prior to the original size plus presence of fever
it is a good indication to remove it. Possibility of it superinfecting to become an abscess
or becoming inflamed is also there.
My suggestion is that you discuss with your doctor the possibility of surgically removing as that is the only option to do away with the pain. The nodule in your neck is most likely a lympadenopathy which is response to a local inflammation (probably from your breast)
Hope this helps