When a suspicious finding or change is detected during a physical exam or mammography, the next step may be to take a small tissue sample, or biopsy, from the area in question. The biopsy tissue is examined by a pathologist, who then determines whether or not the biopsy contains cancerous cells.
Biopsies can be taken by different methods, including:
Fine Needle Aspiration (FNA)
During a fine needle aspiration (FNA), the doctor inserts a very thin needle into the suspicious area in order to withdraw, or aspirate, fluid or cells from the questionable tissue or lump. The pathologist examines these aspirated cells under a microscope to determine whether or not they are cancerous. This type of biopsy is typically quick with little discomfort.
Core Needle Biopsy
If a larger tissue sample is needed or if the tissue removed during a needle aspiration biopsy does not lead to a definitive diagnosis, a core needle biopsy may be required. This procedure requires a local anesthetic to numb the area where the doctor inserts a larger, hollow needle to remove a thin cylinder of tissue, which is then analyzed by a pathologist.
Image-guided biopsy is when the doctor uses ultrasound, stereotactic mammographic imaging or MRI to guide the biopsy needle if the abnormal tissue cannot be seen or felt externally.
If other biopsy procedures do not provide a definitive diagnosis, or if the suspicious area is too deep or too superficial for a fine needle or core biopsy, a surgical biopsy may be needed. This procedure occurs in an operating room, but usually only requires “twilight” or light sedation via an intravenous anesthetic. The surgeon then will make a small incision and remove either the entire mass of suspicious breast tissue or a representative sample, which then will be evaluated by a pathologist. Sentinel node biopsy is a surgical biopsy used to assess whether the cancer has spread beyond the tumor to the lymphatic system, and involves removal of the sentinel nodes for evaluation by the pathologist.