Hi vivian, I have a similar situation and have posted here with really no response from anyone on the situation. In reality you need to keep track of it and also make sure that a medical professional is monitoring it. I have a similar enlarged axillary lymph node, no history of cancers. It has been ultrasounded twice, cat scanned once, biopsied once-came back normal lymph tissue. and had an extra mammogram in addition to my annual....it has now been present over a year with really no new developments or illness or cancer...the only thing it really does is constantly annoy me as I am ever aware of it's presence.
I'm not quite clear as to exactly what this lump is ... a lymph node perhaps ?? You state the biopsy came back as negative but there is usually a lot more to a biopsy report than just "negative". I think after my mammogram if you aren't given a better answer I would ask for a second opinion from either a Breast Specialist or a Breast Surgeon. I don't see how an MRI would be valuable but an Ultrasound might help to define the nature of this ?? lump. If it is in the axillary area I'm not sure the mammogram will include the area in question. I know of nothing in the way of medication or dietary that would reduce the size of the lump. I would be very interested to hear what your mammogram shows or any other test that may be done. Please keep us posted, OK ?? Regards ....