to evaluate the tissue correctly. About 1 in 20 aspirations does not confirm a malignancy when one is known to be present (false negative), so either a repeat FNA, a needle-guided biopsy or an open surgical biopsy should be done if mammography or physical findings are suspicious and the initial FNA is negative.
• Mammography may help guide the surgeon to do an open biopsy of the correct area. This is especially important for non-palpable lesions. A needle is placed within or adjacent to the lesion under x-ray guidance (needle localization). A mammogram is then done to make sure the suspicious area has been removed.
• Stereotactic fine-needle biopsy and core biopsy are specialized mammography procedures, similar to needle localization, that rely on computer assistance to allow a biopsy needle to be positioned even more precisely. These techniques are used mainly for small non-palpable lesions detected by mammography alone.
