Talk to your oncologist or surgeon. Everyone is different. I had lymph node biopsy the same time as my surgery. I had my ultrasound at the same time as the ultrasound of my breast. For me it was mammogram which showed tumor, a repeat mammogram for confirmation, then ultrasound, then biopsy which confirmed cancer. Then I had surgery. One thing you will learn here is that treatment for all of us is often completely different depending on the Grade, Stage, tumor markers, and location of the cancer. Best to talk to your doctors who know all of the information about your particular case.

Usually a sentinel lymph node biopsy is done. A couple of lymph nodes are removed and sent to pathology. If they are clear that's it for lymph nodes. If they show cancer then more are removed to see how many are involved. My biopsy was done while I was having my lumpectomy. The nodes are examined by pathology and the results given to the surgeon while you are still in the operating room.

I have no idea but when two doctors are telling you different things there is nothing wrong with asking for a second opinion.

Also was wondering - do they ever do a needle biopsy of the armpit nodes before you go for surgery and if so, why/when would that be done? My surgeon was saying he was already going to do a sentinel node biopsy by removing the sentinel nodes so when/why would a needle biopsy of the armpit nodes also be done before surgery?