Depending on the location, size and type of lump discovered in the breast, one of four different biopsies can be performed. A needle aspiration biopsy is done by inserting a needle into the breast and removing targeted tissue. An axillary node dissection biopsy tests lymph nodes under the arm to check for spread of the cancer. In an open excisional biopsy, a one to two inch incision is made and tissue removed. The fourth type is sentinel node biopsy in which the sentinel node, the first node to filter fluid from the breast, is removed and examined.