Stereotactic localization biopsy
This is a newer approach that relies on a three-dimensional x-ray to guide the needle biopsy of a nonpalpable mass. With one type of equipment, the patient lies face down on an examining table with a hole in it that allows the breast to hang through; the x-ray machine and the maneuverable needle "gun" are set up underneath. Alternatively, specialized stereotactic equipment can be attached to a standard mammography machine.The breast is x-rayed from two different angles, and a computer plots the exact position of the suspicious area. (Because only a small area of the breast is exposed to the radiation, the doses are similar to those from standard mammography.) Once the target is clearly identified, the radiologist positions the gun and advances the biopsy needle into the lesion.
Tissue Studies
The cells or tissue removed through needle or surgical biopsy are promptly sent (along with the x-ray of the specimen, if one was made) to the pathology lab. If the excised lump is large enough, the pathologist can take a preliminary look by quick-freezing a small portion of the tissue sample. This makes the sample firm enough to slice into razor-thin sections that can be examined under the microscope. A "frozen section" provides an immediate, if provisional, diagnosis, and the surgeon may be able to give you the results before you go home.The results of a frozen section are not 100 percent certain, however. A more thorough assessment takes several days, while the pathologist processes "permanent sections" of tissue that can be examined in greater detail.
When the biopsy specimen is small--as is often the case when the abnormality consists of mammographic calcifications only--many doctors prefer to bypass a frozen section so the tiny specimen can be analyzed in its entirety.
The pathologist looks for abnormal cell shapes and unusual growth patterns. In many cases the diagnosis will be clear-cut. However, the distinctions between benign and cancerous can be subtle, and even experts don't always agree. When in doubt, pathologists readily consult their colleagues. If there is any question about the results of your biopsy, you will want to make sure your biopsy slides have been reviewed by more than one pathologist.
Deciding To Biopsy
Not every lump or mammographic change merits a biopsy. Nearly all mammographic masses that look smooth and clearly outlined, for instance, are benign. Your doctor needs to thoughtfully weigh the findings from your physical exam and mammogram along with your background and your medical history when making a recommendation about a biopsy.In general, doctors feel it is wise to biopsy any distinct and persistent lump.
Although benign lumps rarely, if ever, turn into cancer, cancerous lumps can develop near benign lumps and can be hidden on a mammogram. Even if you have had a benign lump removed in the past, you cannot be sure any new lump is also benign.
In some cases, the doctor may suggest watching the suspicious area for a month or two. Because many lumps are caused by normal hormonal changes, this waiting period may provide additional information.
Similarly, if the changes on your mammogram show all the signs of benign disease, your doctor may advise waiting several months and then taking another mammogram. This would be followed by more diagnostic mammograms over the next 3 years. If you choose this option, however, you must be strongly committed to regularly scheduled followups.
If you feel uncomfortable about waiting, express your concerns to your doctor. You may also want to get a second opinion, perhaps from a breast specialist or surgeon. Many cities have breast clinics where you can get a second opinion.
