Dear Peggie, The BIRAD rating 4 means that the mammogram has been read as a suspicious looking abnormality that is not characteristic but has a reasonable probability of malignancy. A biopsy should be considered.
The recommendation for a biopsy is made based on the surgeon's physical assessment as well as assessment of the mammogram. A biopsy is recommended that would be what has the best chance of answering the question whether this is malignant or not, and getting that answer in a way that is least invasive.
I sounds like the type of biopsy your surgeon is talking about is a needle localization (wire localization) biopsy. With this type of biopsy a thin wire is used to show the surgeon where the lesion is. This is done when a lesion cannot be felt and a needle biopsy is not possible. A wire is usually placed in the x ray department. The radiologist gives a local anesthetic, put a small needle into your breast under x-ray guidance, pointing toward the cluster of calcifications. Then a very thin wire is passed through and positioned so the end is in the midst of the calcifications. The wire is left in place and you are taken to the operating room. Here the surgeon gives more local anesthetic, makes an incision, follows the wire, and then takes out the area of tissue around it. The tissue is sent to the radiology department where it is x-rayed to make sure it's from the area with the calcifications and then sent to the pathology department. The surgeon then sews up the small incision. The x-ray of the tissue lets you know if the surgeon got the calcifications or area that was seen on the mammogram.
Another type of biopsy that might be used in the situation of calcifications on a mammogram is a stereotactic biobsy. With a stereotactic biopsy, computer-assisted X-rays allow the biopsy needle to be precisely positioned, especially for smaller lumps or lumps that cannot be felt. Special mammogram films are taken of the site to be biopsied. The radiologist uses these films and, with the assistance of a computer, calculates the exact location for needle placement to obtain the biopsy. The procedure begins with cleansing the skin and applying a local anesthetic to numb the skin surface. The radiologist then introduces a sterile biopsy needle. Additional X-ray films are taken to confirm accurate needle placement. Tissue samples are obtained through the needle. It is standard procedure for the needles to be inserted three to five times in order to obtain an adequate tissue sample, this portion of the procedure takes ten minutes or less. The biopsy site is so small, a Band-Aid is usually all that is applied, and a woman can resume her normal activities after the procedure is completed. The entire procedure takes about one hour.
If an area seen on mammogram is not palpable (feelable) there are two ways to biopsy it: needle localization, wherein a radiologist guides a wire into the area using xray guidance, following which the surgeon operates and follows the wire to the area and removes it. The other is a stereotactic biopsy where the area is sampled by an xray guided passsing of a special needle into the area which removes samples of tissue. The latter is done entirely by the radiologist, without "surgery." Choosing one over the other depends on several things, including the anatomy of the breast and whether the calcifications are clustered tightly together, etc. Usually a stereotactic biopsy can be done, and gives very reliable results. Sometimes the location within the breast makes that technique more difficult. As to the percentages of finding cancer, even though the categories are supposed to be sort of black and white, they aren't entirely. It sounds like you need a biopsy. Without sounding trite, it will be what it will be. Odds apply to a thousand women, but don't really help the individual to know what to expect.