There are two categories of biopsies:
Fine-needle aspiration does not use local anesthesia. Core biopsies usually use a local anesthetic injected into the skin. If the tissue to be sampled is deep in the breast, a nick is made in the skin and a needle is used to insert anesthetic. Core biopsy may be uncomfortable, but should not be a painful procedure. If it is, tell the doctor performing the procedure so additional anesthesia can be used.
Fine-needle aspiration (FNA) biopsy. This procedure uses a small hollow needle to remove (aspirate) a small amount of fluid or cells. It can be performed by a surgeon, a radiologist or a pathologist, but is best done by someone who performs many of these biopsies. FNA is sometimes used when a lump or mass can be clearly felt through the skin. FNA is often done in a doctor's office. The procedure will not cause a scar. An attempt is made to withdraw fluid from the lump. If fluid can be withdrawn and is clear fluid, this is a cyst. If fluid cannot be aspirated, cells in the needle are placed on a slide and sent to the pathologist to review.
Based on the results of your pathology report, the physical exam, the mammogram or ultrasound reports, your surgeon can then decide whether the lump should be surgically removed.
Ultrasound-directed needle biopsy. This procedure is useful when a lump or mass can be seen on ultrasound but cannot be felt. It cannot be relied on for biopsy of microcalcifications. The procedure is essentially an FNA biopsy done with a special machine called an ultrasound to ensure that the needle is in the right place. An instrument that resembles a microphone is rubbed over the area of concern in the breast. The ultrasound bounces sound waves on the breast tissue and the resulting image on a screen is used to pinpoint where the needle should be inserted.
Stereotactic core needle biopsy. This procedure is useful for findings that are visible on a mammogram and that cannot be felt through the skin, such as microcalcifications. It is a specialized procedure using computerized mammogram equipment. The patient can be biopsied sitting up or lying on her stomach, depending on the equipment used by the center. If she is lying on her stomach, the breast hangs through an opening in a special table. The radiologist uses a mammogram paddle to compress the breast, then very carefully pinpoints the suspicious area using mammography. The area is then numbed with a local anesthetic and the doctor makes a tiny cut and inserts a special biopsy probe. This probe takes several small cores of tissue from the area in question. The procedure is short, generally taking less than one hour, and the woman can go home immediately afterward with just a small bandage on her breast. A small, usually round scar may result, but rapidly fades. For post biopsy pain, wearing a snug fitting bra and applying ice compresses is helpful.
Some women are not candidates for this type of biopsy for technical reasons, such as having breasts that are too small for the biopsy probe, or if the suspicious finding is either very superficial or very deep in the breast. Also, the patient may need to lie still for 30 minutes or more. If a patient cannot lie on her abdomen on the X-ray table or is unable to lie still for any reason, she may not be a candidate for stereotactic biopsy.
Wire-localization biopsy. This is a preoperative procedure performed by a radiologist just before the patient is taken to surgery. The objective is to pinpoint a mammogram finding, such as microcalcifications that cannot be felt through the skin. Using a mammogram X-ray machine for guidance, the area in question is located and a hollow needle is inserted. A thin wire is then inserted through the needle into the area of concern. After the wire is placed, another mammogram is gently taken to ensure that the wire is in the right location. Once placement is correct, the needle is withdrawn and the wire is left in place. The patient is then taken to the operating room along with the mammogram films. The wire assists the surgeon in accurate location and removal of the abnormal area, and helps avoid unnecessary removal of healthy tissue. This is an outpatient procedure, and may be done with local anesthesia or conscious sedation where you are asleep during the procedure, but quickly wake up. Once the tissue is removed and while the patient is still on the operating table, the tissue is X-rayed to ensure that it matches the suspicious area on the mammogram and to help orient the pathologist.
This procedure is more likely to be used if the patient is not suitable for a stereotactic biopsy procedure. It is also necessary if either DCIS or cancer is diagnosed by a stereotactic core biopsy and an area of the breast must be removed.
Excisional biopsy. This surgical procedure removes an entire mass or lump, including a small margin of normal tissue around it. It is the most common type of surgical biopsy. It is not used alone for microcalcifications since these cannot be seen nor felt.
Which kind of biopsy Is best?
If the tissue sampled is not the right area to be sampled, then the patient may have a falsely benign diagnosis. Mammographic correlation with any image-guided biopsy should be mandatory.
The most common biopsies for microcalcifications are the stereotactic core-needle biopsy and the wire localization biopsy. Studies have compared the different kinds of biopsies to determine whether one is better than another for tissue sampling and for minimizing discomfort and scarring. The sensitivity and specificity of stereotactic core-needle biopsy for diagnosing DCIS is comparable to wire localization and open surgical biopsy. The most important criteria for biopsy is the amount of experience the surgeon or radiologist has in doing the procedure. The more experience, the more accurate the diagnosis is likely to be.