Ask the Doctor: What I Should Know About a Breast Biopsy
by Dr. C.H. Weaver M.D. updated 9/2020
A breast biopsy involves the removal of a sample of cells or tissue from the breast. This sample is then examined under a microscope to look for signs of cancer.
When and why are breast biopsies recommended?
Your doctor may recommend a breast biopsy if you develop a lump in your breast or experience other breast changes. Biopsy results can indicate whether or not the suspicious areas are the result of breast cancer or a benign (non-cancerous) condition.
Will a breast biopsy hurt?
You can receive a local anesthetic before you undergo a biopsy, so the procedure is unlikely to be painful.
Are there different kinds of biopsies?
The two main types of biopsies are needle biopsies and surgical biopsies. You and your doctor will choose which procedure is most appropriate based on the location and size of the suspicious area, your general health, and your preference. There are risks and benefits with both kinds of biopsy.
How is each type of biopsy performed?
Needle biopsies are simple, fast procedures that are usually performed in the outpatient setting with local anesthesia. A needle is used to remove cells or a small amount of tissue from the suspicious area. If the abnormal area cannot be felt but only seen on a mammogram or MRI, your doctor can use additional equipment (such as ultrasound imaging or MRI) to guide the needle.
There are three types of needle biopsies:
- Core needle biopsy—In this procedure a doctor uses a thin, hollow needle to remove a small tissue sample.
- Fine needle aspiration—An even thinner needle than the needle used for a core needle biopsy is used in this procedure. The needle removes a few cells from the suspicious area.
- Vacuum-assisted biopsy—This procedure can remove cores of tissue by using a thicker, hollow needle and a vacuum-assisted probe. If your doctor cannot feel the abnormal area, ultrasound imaging as well as stereotactic mammography can be used to guide the needle.
The most common type of surgical biopsy is an excisional biopsy. This involves the removal of the entire breast lump as well as some surrounding normal tissue. Though more invasive than needle biopsy, excisional biopsy is the most accurate way to diagnose breast cancer. As well, because the entire tumor is removed, this procedure may be the only surgery needed to both diagnose and treat breast cancer. Surgical biopsies can be done in the hospital or in the outpatient setting, and anesthesia is used.
What are the advantages and disadvantages of both needle and surgical biopsies?
Needle biopsies are less invasive, faster, and less expensive than surgical biopsies but have some limitations. For example, if a needle biopsy result is inconclusive or the needle misses the tumor, a surgical procedure may still be necessary. As well, because the lump is not removed, additional surgery may be required if cancer is found.
A surgical biopsy is more accurate than a needle biopsy, provides more information needed for treatment planning, and because the entire lump is removed, may be the only surgery required. However, because this is an open surgical procedure, there is a higher risk of infection, scarring, and changes to the breast in appearance and feel.
What should I talk to my doctor about before I undergo a biopsy?
In addition to details about the biopsy itself (such as the choice of procedure and amount of lump removed), be sure to ask your doctor how the procedure will affect you. Important details include: How long will the biopsy take? Can I go home on the same day? How much scarring can I expect? Are there any possible side effects? As well, find out when you’ll receive the results of the biopsy—the waiting period can be stressful, so it’s helpful to know when to expect results.
Q. What exactly is a breast biopsy, and what is the pathologist looking for?
A. Women usually undergo a breast biopsy to have a suspicious area of breast tissue examined. Such suspicious areas are typically discovered during a clinical breast examination or via breast imaging (such as a mammogram). During a breast biopsy, a small tissue sample from the abnormal area is removed and examined by a pathologist using a microscope to check for breast cancer.
The sample may also be sent for NGS biomarker testing to determine if cancer driving mutations are present that can be treated with precision cancer medicines.
Q. What is the difference between an open surgical breast biopsy and a needle breast biopsy?
A. An open biopsy is a surgical procedure that requires local or general anesthesia and an incision in the breast to remove the abnormal area. A minimally invasive breast biopsy—also called a needle biopsy—is a simpler procedure in which the patient is given local anesthesia before a small, hollow needle is carefully guided into the suspected region, using the same imaging modality on which the abnormality was best visualized. A minimally invasive biopsy removes a core needle sample, resulting in no more than a 3-millimeter scar, whereas an open biopsy can leave scarring and indentation. With a needle biopsy, there is no need for general anesthesia, so it does not come with the risks associated with surgery.
Q. What are the risks and costs associated with each type of breast biopsy?
A. An open surgical biopsy carries the risk of infection, blood loss, and scarring, as an incision is made during the procedure that then has to be stitched closed. An open biopsy costs three to four times more on average than a needle biopsy.
Only about 15 to 20 percent of abnormalities detected by mammography turn out to be cancerous. Given that 80 to 85 percent of lesions are benign, a definitive diagnosis of cancer should be made using a needle biopsy as the first diagnostic step for all breast abnormalities. This allows for optimal preoperative workup and planning if cancer is found. It also gives a woman time to talk about various treatment options with her doctor to decide what’s best for her.
The American College of Surgeons published guidelines sanctioning the minimally invasive breast biopsy as the recommended procedure for diagnosing image-detected lesions, and the American Society of Breast Surgeons issued a statement in accordance with these guidelines. It is a quality standard that is advocated and embraced by most breast cancer organizations.
Q. Given that a needle biopsy is considered the gold standard, under what circumstances would an open biopsy be necessary?
A. There are relatively few women for whom an open surgical biopsy is medically necessary as the initial diagnostic procedure, but there are of course rare exceptions. In fewer than 5 percent of cases, it might not be possible to biopsy a lump with a needle due to positioning.
Q. What can I expect during and after a needle biopsy?
A. During a needle biopsy, you will remain awake, and your breast will be numbed with a local anesthetic. The lump will be located with image guidance, or by touch, and a core needle will be inserted through your skin into the lump to remove the sample tissue. Three to six samples are usually taken to ensure accuracy. Women should expect to feel some pressure but not any significant pain. After the procedure, you may experience slight bruising at the needle sites, but you will be able to carry on with your regular routine. A pathologist will examine the tissue samples, and a written report will be sent to your doctor with the results.
Q. Who performs a needle biopsy, and how can I locate the most qualified specialist in my area?
A. A surgeon or radiologist can perform a minimally invasive breast biopsy. Radiologists should be certified by the American Board of Radiology, and surgeons should be certified by the American Board of Surgery.
If an open breast biopsy has been recommended for you, it’s important to seek a second opinion. Ask the surgeon or breast center you’ve been referred to about their rates for an open surgical biopsy versus a minimally invasive biopsy and ask if they take a specific position on breast biopsy techniques.
- Approximately 1.6 million women undergo breast biopsies annually.
- The American College of Surgeons and the American Society of Breast Surgeons both concur that a minimally invasive breast biopsy is the procedure of choice for image-detected abnormalities.
- Despite the fact that a needle biopsy is considered the gold standard in breast biopsy, a recent study showed that 40 percent of women are undergoing unnecessary open surgical breast biopsies.
- Only about 15 to 20 percent of abnormalities detected by mammography turn out to be cancerous.
- The accuracy rates for needle breast biopsies are equal to those for open surgical biopsies but with lower cost and less pain, scarring, and risk.