Dear Angiejr29: The concern with a FNA in the setting of a concerning mammogram and ultrasound is that the FNA which takes a sample only the size of the needle, could have missed something. By removing the lump (excisional biopsy), the entire lump will be examined by pathology and nothing will be left to question. As an aside, if the lump is painful, an excisional biopsy may help this as well. In the end, the test that is most correct is the pathology (but examining the entire lump is critical to making sure this is most complete).
Whether the Ultrasound or the FNA is the more correct really isn't the point here. If the Dr. has doubts and recommends an excisional biopsy DON'T HESITATE TO CONSULT A BREAST SURGEON AND PROCEED !!! This way you will know with 100 % certainty the cause of the problem. Best of Luck .......