Breast imaging

Can someone explain to me after having an unltrasound at the Diagnostic Imaging and it was determined that the lump was a lymph node non-suspicious by both technician and the Radiologist I should still considered having a core biopsy? 

Also if I decided to have the core biopsy will the lymph node be removed at that time or just breast tissue.  

I am 56 years old and it had been 10 years since I had a mammogram so I'm not sure if this lymph node has always been there or just appeared.

 

The findings of the second ultrasound was suggestive of a benign intramammary lymph node.  Is this something I should be concerned about and should I get a second opinion before I reschedule a biopsy or can I wait until my six month check up?

I would definately get a second opinion.  There are some imaging places that routinely see suspicious things just to refer you for more tests.  My mom, sister and myself all went to the same place and we were all told that we needed biopsies.  We got second opinions elsewhere and none of us needed a biopsy.  We found out later that several of our friends were being told the same thing.  So get a second opinion just to be safe.