breast biopsy breast biopsy a breast biopsy is usually done after a suspicious lesion is discovered on either mammography or ultrasound to get tissue for pathological diagnosis. several methods for a breast biopsy now exist. the most appropriate method of biopsy for a patient depends upon a variety of factors, including the size, location, appearance and characteristics of the abnormality. the different types of breast biopsies include fine-needle aspiration (fna), vacuum-assisted biopsy, core needle biopsy, and surgical excision biopsy. breast biopsies can be done utilizing ultrasound, mri or a stereotactic biopsy imaging guidance. vacuum assisted biopsies are typically done using stereotactic techniques when the suspicious lesion can only be seen on mammography. on average, 5–10 biopsies of a suspicious breast lesion will lead to the diagnosis of one case of breast cancer. needle biopsies have largely replaced open surgical biopsies in the initial assessment of imaging as well as palpable abnormalities in the breast.