By Carol Harbers

It is possible that -- like thousands of women in this country -- you could find a lump in your breast this year.

The good news is that the statistics are on your side: the vast majority of suspicious masses in the breast -- about four out of five -- are benign. To know for sure, your doctor might recommend a biopsy.

What can your doctor learn from breast biopsy? How are they performed?

We asked Duke Cancer Institute breast surgeons Lisa Tolnitch, MD, and Shelley Hwang, MD, these questions and more. 

Lisa Tolnitch, MD

Why do I need a biopsy?

Tolnitch: Any persistent, suspicious mass or abnormality detected by ultrasound or mammogram needs a biopsy to determine whether it is benign or cancerous. A scoring system called BIRADS (Breast Imaging Reporting and Data System) helps us determine which lumps require follow-up. A BIRADS score of 4 or 5 should be biopsied.

How are they done?

Tolnitch: Most often, a surgeon, primary care doctor, or ob-gyn does a biopsy in their office with a core needle. A core needle is hollow and can remove cores of tissue, but not the entire lump or mass.

Shelley Hwang, MD

The procedure can also be done with vacuum assistance, which provides a larger tissue sample. A small incision is necessary with vacuum-assisted core needle biopsy. The biopsy can also be done under ultrasound or mammogram guidance -- which helps the doctor better visualize the mass during the procedure.

Hwang: There is usually a mammogram machine or ultrasound machine in the room, as well as an assistant to collect the biopsy specimens. For mammogram-directed biopsies (“stereotactic” biopsies), the patient will be on her stomach; for ultrasound-guided biopsies, the patient lies on her back.

The procedure is handled quickly with expertise and compassion. Nurses are with you throughout to support, comfort, and help you in any way you need.

How much can you learn from a biopsy? How accurate are they?

Hwang: Biopsies can tell us whether or not a lump is cancerous and, if it is cancerous, what type and stage it is.

Biopsies are highly accurate, but patients need to keep in mind that there is a sampling error. That is, if the whole abnormality is not removed, only the portions that are removed can be evaluated. This is why, even after a negative biopsy, patients are followed for a period of time with clinical and radiographic examination.

Often, a tiny metal clip is placed at the biopsy site so that the area of the biopsy can be followed in subsequent mammograms. The clip does not cause pain and cannot be felt by the patient, but it allows the biopsy site to be seen on future mammograms.

Tolnitch: If the lump is malignant, biopsies can tell us a lot about the cancer, including its biochemical composition and the genomic makeup.

This information helps determine a treatment plan.

What about recovery?

Hwang: Recovery takes just one day. Sometimes the patient can have some bruising afterwards, but this generally takes care of itself. Infections can also occur, but that is very rare.

Tolnitch: I suggest that patients take a Tylenol or Advil after the biopsy and wear a bra to sleep in that night.

How long do I have to wait for the results?

Tolnitch: Results are available in 24 to 48 hours. You are given contact information for questions that may arise after the biopsy.

How far have we come with breast biopsies?

Tolnitch: Biopsies are more accurate and easier than in the past because the technology of the needles and of ultrasound and digital imaging has advanced. Image-directed biopsies today require a single insertion of a needle under local anesthesia and can be accomplished in a short time.

Shelley Hwang, MD, treats patients at the Duke Cancer Center in Durham; Lisa Tolnitch, MD, at Tolnitch Surgical Associates, a Duke surgical oncology practice in Raleigh.