Breast BiopsyThe only certain way to learn whether a breast lump or mammographic abnormality is cancerous is by having a biopsy, a procedure in which tissue is removed by a surgeon or other specialist and examined under a microscope by a pathologist. A pathologist is a doctor who specializes in identifying tissue changes that are characteristic of disease, including cancer.
Tissue samples for biopsy can be obtained by either surgery or needle. The doctor's choice of biopsy technique depends on such things as the nature and location of the lump, as well as the woman's general health.
Surgical biopsies can be either excisional or incisionalAn excisional biopsy removes the entire lump or suspicious area. Excisional biopsy is currently the standard procedure for lumps that are smaller than an inch or so in diameter. In effect, it is similar to a lumpectomy, surgery to remove the lump and a margin of surrounding tissue. Lumpectomy is usually used in combination with radiation therapy as the basic treatment for early breast cancer.
An excisional biopsy is typically performed in the outpatient department of a hospital. A local anesthetic is injected into the woman's breast. Sometimes she is given a tranquilizer before the procedure. The surgeon makes an incision along the contour of the breast and removes the lump along with a small margin of normal tissue. Because no skin is removed, the biopsy scar is usually small. The procedure typically takes less than an hour. After spending an hour or two in the recovery room, the woman goes home the same day.
An incisional biopsy removes only a portion of the tumor (by slicing into it) for the pathologist to examine. Incisional biopsies are generally reserved for tumors that are larger. They too are usually performed under local anesthesia, with the woman going home the same day.
Whether or not a surgical biopsy will change the shape of your breast depends partly on the size of the lump and where it is located in the breast, as well as how much of a margin of healthy tissue the surgeon decides to remove. You should talk with your doctor beforehand, so you understand just how extensive the surgery will be and what the cosmetic result will be.
Needle biopsiesPerformed with either a very fine needle or a cutting needle large enough to remove a small nugget of tissue.
- Fine needle aspiration
uses a very thin needle and syringe to remove either fluid from a
cyst or clusters of cells from a solid mass. Accurate fine needle
aspiration biopsy of a solid mass takes great skill, gained
through experience with numerous cases.
- Core needle biopsy uses a somewhat larger needle with a special cutting edge. The needle is inserted, under local anesthesia, through a small incision in the skin, and a small core of tissue is removed. This technique may not work well for lumps that are very hard or very small. Core needle biopsy may cause some bruising, but rarely leaves an external scar, and the procedure is over in a matter of minutes.
At some institutions with extensive experience, aspiration biopsy is considered as reliable as surgical biopsy; it is trusted to confirm the malignancy of a clinically suspicious mass or to confirm a diagnosis that a lump is not cancerous. Should the needle biopsy results be uncertain, the diagnosis is pursued with a surgical biopsy. Some doctors prefer to verify all aspiration biopsy results with a surgical biopsy before proceeding with treatment.
Localization biopsyAlso known as needle localization,this is a procedure that uses mammography to locate and a needle to biopsy breast abnormalities that can be seen on a mammogram but cannot be felt (nonpalpable abnormalities). Localization can be used with surgical biopsy, fine needle aspiration, or core needle biopsy.
For a surgical biopsy, the radiologist locates the abnormality on a mammogram (or a sonogram) just prior to surgery. Using the mammogram as a guide, the radiologist inserts a fine needle or wire so the tip rests in the suspicious area -- typically, an area of microcalcifications. The needle is anchored with a gauze bandage, and a second mammogram is taken to confirm that the needle is on target.
The woman, along with her mammograms, goes to the operating room, where the surgeon locates and cuts out the needle-targeted area. The more precisely the needle is placed, the less tissue needs to be removed.
Sometimes the surgeon will be able to feel the lump during surgery. In other cases, especially where the mammogram showed only microcalcifications, the abnormality can be neither seen nor felt. To make sure the surgical specimen in fact contains the abnormality, it is x-rayed on the spot. If this specimen x-ray fails to show the mass or the calcifications, the surgeon is able to remove additional tissue.