What Is a Breast Biopsy?

A breast biopsy is a procedure in which a sample of breast tissue is obtained surgically so it can be tested for breast cancer. There are several methods available to obtain the sample.

Your healthcare team will recommend an approach that is likely best for you. Overall, 70%–80% of biopsies are negative for cancer, and some show signs of benign breast diseases or conditions that increase the risk of breast cancer.

This article will explain a breast biopsy, including the purpose, types of biopsy available, risks, contraindications, and interpretation of the results.

Purpose of Test

A breast biopsy may be recommended if a person develops symptoms of breast cancer, or if an abnormality is found on a screening test. The most common breast screening test is a mammogram. Depending on the mammogram findings follow-up imaging such as breast ultrasound or breast magnetic resonance imaging (MRI) may be recommended.

While the procedure is more commonly done for women, some men may need a biopsy because men can also develop breast cancer. The information in this article is relevant regardless of sex or gender.

Symptoms of breast cancer can include:

• A breast lump
• Breast dimpling
• Orange peel appearance of the breast
• Skin thickening on the breast
• Nipple changes, such as a retracted nipple
• Nipple discharge
• A red rash or sores on the breast
• Enlarging veins on the breast
• A change in size, shape, or weight of a breast
• An enlarged lymph node in the armpit

Findings on imaging tests that may suggest the need for a biopsy include:

• The presence of microcalcifications (small calcium deposits) or a spindle-shaped mass on mammogram
• A solid or partly solid lump on breast ultrasound
• A mass with irregular borders on a breast MRI (magnetic resonance imaging)

Women who have a high risk of developing breast cancer are often screened with a combination of MRI and mammogram. 

High-risk categories for breast cancer include:

• Family history of breast cancer
• Genetic mutations linked with breast cancer (for example, the BRCA gene)

In one study, MRI screenings triggered more breast biopsies than mammograms alone and these biopsies were less often positive for cancer.

Occasionally, the medical provider diagnoses breast cancer because of metastases (cancer that has spread) to another region of the body (such as the bones, liver, lungs, or brain). In these situations, the breast biopsy is done to confirm the primary cancer type and location. 

Types of Breast Biopsy

Based on your symptoms and preliminary tests, your healthcare provider will determine which type of biopsy is most appropriate for you.

A breast biopsy may be done in one of several ways:

• Fine needle aspiration (FNA): This involves the insertion of a thin needle through the skin to collect a sample of cells. It is most often used if a lump is palpable (can be felt through the skin). This approach is particularly helpful in distinguishing fluid-filled cysts from solid masses.
• Core needle biopsy: Compared to FNA, a slightly larger sample of tissue is collected with a large needle. Ultrasound or MRI for guidance are usually used during the procedure.
• Open (surgical) biopsy: An open biopsy is collected with a surgical procedure that involves cutting into the skin and breast tissue. Ultrasound guidance, MRI guidance, stereotactic placement (using 3D-guided imagery), or wire localization may be needed to locate the abnormality. There are two general types of open biopsy:
• Incisional biopsy: Removes part of the abnormality
• Excisional biopsy: Removes all of the abnormality, as well as a margin of normal tissue
• Skin biopsy or nipple biopsy: A sample of the breast skin or nipple skin is collected if inflammatory breast cancer or Paget's disease of the nipple is suspected

Limitations

With a fine needle biopsy, only a small sample is collected. It is not usually possible to determine the tumor grade (aggressiveness), the size of the tumor, or whether receptors (such as estrogen receptors) are positive or negative from a fine needle biopsy.

If the results of a fine needle aspiration or core biopsy are unclear, an open biopsy is usually recommended by the medical provider.

All types of breast biopsies carry the risk of false positives and false negatives.

• False negatives occur when a cancer is present but the biopsy doesn't detect it. It is more common with fine-needle aspiration and least common with an open surgical biopsy. False negatives are more common when a breast mass cannot be felt on a physical exam.
• False positives occur when a biopsy suggests cancer is present when it is actually not. In a 2015 study published in the Journal of the American Medical Association (JAMA), false-positive findings were noted on 17% of breast biopsies. False-positive diagnoses were less likely to occur with invasive cancer and more commonly seen with ductal carcinoma in situ (DCIS) and atypical hyperplasia.

Risks and Contraindications

Your provider will discuss the benefits of the procedure and the risks involved. There may be reasons your medical provider recommends not having a test done. These are known as contraindications.

Potential Risks

Bleeding and infection are potential risks of any type of breast biopsy. Make sure the provider knows about any medications you are taking, especially blood-thinning medications or anything that weakens your immune system.

There are risks associated with local and general anesthesia. Tell your team about any allergies you have and any history of anesthesia reactions for you or your family members. 

There is a very small risk that the needle used for a fine needle or core biopsy may penetrate the lungs and cause a pneumothorax (collapse of a lung). This is more common when the biopsy site is very deep in the breast.

Core needle biopsy poses a small risk of seeding tumor cells along the track of the needle, increasing the risk of metastases.

Some surgical biopsies can lead to scarring or disfigurement of the breast, especially when large amounts of tissue are removed. Your provider should discuss expected outcomes with you before performing the procedure.

Contraindications

Considerations that may rule out a breast biopsy include:

• For women who are breastfeeding, there is a risk of a milk fistula (abnormal collection of milk between the skin surface and milk duct in the breast).
• For women with silicone breast implants, a core needle biopsy may not be advisable.
• The tables used for stereotactic biopsies often have a weight limit of 300 pounds.
• Stereotactic localization involves radiation, and benefits and risks need to be weighed carefully for pregnant women.

Your team will discuss your specific situation with you and provide you with a personalized treatment plan. Be sure to ask any questions and raise any concerns you may have with your providers.

Before the Test

Your practitioner will review your risk factors for breast cancer. Expect to share your menstrual history, the number of pregnancies you have had, and any family history of breast cancer or other cancers.

Your healthcare provider will discuss with you the reason for your procedure and the possible risks.

Timing

The amount of time required for a breast biopsy depends on the kind of biopsy. When your biopsy is scheduled, the healthcare team will inform you about what to expect. 

• A needle biopsy may take five to 10 minutes.
• A core biopsy may take 15 to 30 minutes but may require more time if ultrasound or MRI guidance is needed.
• You should set aside several hours for an open biopsy, which can involve preparation and recovery time. If wire localization or a stereotactic procedure is done, this can take up to an hour or more of additional time.

Location

A needle biopsy or core biopsy may be done in a clinic, or in a radiology department if ultrasound guidance is needed. Open surgical biopsy is usually done in an outpatient surgery center or as an outpatient procedure at a hospital.

What to Wear

You will be asked to remove your clothing and change into a gown before your biopsy procedure (usually just from the waist up for a needle or core biopsy). Afterward, plan to wear a supportive, but not tight, bra for up to a week.

Food and Drink

Usually, there are no dietary restrictions for a needle or core biopsy. For a surgical biopsy, you will likely be asked to avoid eating or drinking anything after midnight the day before the procedure.

Medications

You should talk to your healthcare provider about any medications, vitamins, supplements, or herbs that you take. Often, it is recommended that blood thinners, aspirin, and anti-inflammatory medications like Advil (ibuprofen), or supplements that cause bleeding be stopped for a few days before the procedure to reduce the risk of bleeding.

Don't make changes to your regular medications unless advised to do so by your healthcare provider.

Smoking

If you smoke, quitting before your biopsy reduces the risk of infection and improves wound healing. Refraining from smoking for even a day or two prior to your procedure may have benefits.

Cost and Health Insurance

Most private insurers, as well as Medicare, cover the cost of a breast biopsy. With some insurance companies, or when special techniques are recommended, you may need to obtain prior authorization.

What to Bring

When you schedule your biopsy, you will likely receive a list of things to bring to the test.

Expect to bring your:

• Insurance card
• Photo identification, such as driver's license or state ID
• Imaging tests: Original films or a CD of images are best
• Biopsy reports from any previous tests
• Medication list: Bring a list of all prescription medications, over-the-counter medications, and supplements you take

It can be a good idea to bring a book, magazine, or another item to entertain yourself during downtimes.

Other Considerations

If you will be having a surgical biopsy, you will need to bring a companion who can drive you home. 

A needle or core biopsy is usually done with local or regional anesthesia (numbing medicine). You may receive medications to help you relax for the procedure that can interfere with driving. Check with your provider to see if you should arrange for someone to drive you home.

What to Expect During Your Biopsy

Each facility has slightly different protocols and procedures, but you will find a general idea of what to expect below.

Pre-Test

A nurse, your surgeon, and your anesthesiologist will talk to you before your procedure. You will be asked to sign an informed consent form indicating that you understand the purpose of the procedure and any potential risks. You will have time to ask any questions about your procedure as well.

You will be asked to change out of your clothes and into a gown. You will be escorted to the testing area. Your provider will check your vital signs. Your surgeon will confirm the location of the biopsy. They will examine your lump if you have one.

If needed, your team will place an IV (intravenous line). The staff will attach monitors that will record your heartbeat, blood pressure, and the oxygen level in your blood.

Throughout the Test

The breast biopsy procedure will vary depending on the type of biopsy you are having.

Stereotactic Breast Biopsy

If you are having a stereotactic breast biopsy procedure, you will lie on your stomach with your breast hanging through a special hole in the table. Digital mammogram images are taken from different angles to create a three-dimensional view of the breast.

When the precise location of the lesion is defined, a needle biopsy may be done or the target area may be marked with a wire for an open biopsy.

Fine Needle Biopsy (FNA)

Before a fine needle aspiration, your skin will be cleansed with a disinfectant. The area will be numbed and a long, narrow needle will be placed into the lump. A syringe will be attached to provide suction. 

• If fluid is present in the sample (such as with a cyst) the fluid will be withdrawn. With a simple cyst, the procedure may make the lump disappear completely.
• If the lump is solid, a collection of cells will be removed and collected for lab analysis.

Once the sample is obtained, the needle and syringe are removed and the area is covered.

Core Needle Biopsy

Before a core needle biopsy, the skin is disinfected and local pain medication is injected.

• A small cut is made in the skin and a needle is inserted through the skin and into the mass.
• This is often done with imaging guidance, even if a lump can be palpated. You may feel some pressure or a tugging feeling while the needle enters your breast.
• A vacuum-assisted core biopsy may be done, in which suction is attached to the hollow needle. It is used to obtain a larger sample of tissue than a typical core biopsy.
• When the healthcare provider is certain the needle is in the correct area, a spring-loaded instrument is used to obtain a grain-sized sample of tissue. Often, four to eight core samples are taken.
• After the sample is collected, a clip is often placed in the region of the biopsy so that it can be identified during a future mammogram or surgery. (This clip will not be a problem if an MRI is needed.)
• Then the needle is removed and pressure is placed on the wound for several seconds before the surgical dressing is applied.

Surgical (Open) Biopsy

In the operating suite, you are asked to lie on your back. Your breast is cleansed with a disinfectant. 

The procedure may be done with a general anesthetic so you are asleep throughout the procedure. Sometimes, the team will perform the biopsy with sedation (“twilight” sleepiness) and a local anesthetic instead. 

If you are receiving a local anesthetic to numb the area, you may feel a pinch when the needle penetrates your skin.

Next, the surgeon will make an incision. If you are awake, you may feel pressure and a tugging sensation as the tissue is removed. The goal is to remove the tumor and to get clear margins of healthy surrounding tissue with the sample.

If needed, the incision is closed with sutures. Surgical dressings are applied to keep the surgical site clean and dry.

Post-Test

The sample(s) collected are sent to a pathologist (physician who examines body tissue) for review. Your provider will let you know what to expect. It typically takes a few days to get your results.

With a needle or core biopsy, you will be watched for a short while and be able to return home as soon as you are feeling comfortable.

With a surgical biopsy, you will be observed in the recovery room until you are awake. You may be given crackers and juice. Once you are fully awake and comfortable, your monitors will be removed and you may return home.

After the Test

With a needle or core biopsy, you will be asked to keep the puncture site clean and dry, and you may be advised to remove the dressing in a day or two. Some bruising and aching are normal. Your healthcare provider may recommend that you sleep in your bra to keep pressure on the site for a few days. It is best to avoid strenuous activity for the first several days.

With an open biopsy, you may be asked to leave your surgical dressings in place until you follow up with your practitioner. Some healthcare providers advise wearing a bra around the clock to provide compression and reduce bruising.

During this time, you should avoid bathing or showering so you keep the site clean and dry. Depending on your provider’s instructions, you may be allowed to give yourself a sponge bath and wash your hair in the sink or tub. The arm on the side of your biopsy may be sore, and you may need help with some of your day-to-day activities.

Managing Side Effects

Usually, there are few, if any, symptoms after a fine-needle aspiration. Typically symptoms are mild after a core biopsy. Your recovery may take longer after an open biopsy. You may have swelling and discomfort for a few days, depending on the size of your biopsy.

Follow the instructions from your provider.

A few things that may help:

• Ice packs
• Supportive bra
• Tylenol (acetaminophen) to ease the pain

Plan to rest for a few days. Your medical team will let you know about any activity limitations or movement restrictions that you should follow.

Interpreting Results

Your healthcare provider may call you or ask that you return to the clinic to discuss your results. You might receive a preliminary report at the time of the biopsy, but the final pathology report takes a few days to complete.

Biopsy results are defined as negative, positive, or inconclusive. If your results are inconclusive, another biopsy or other studies may be needed.

Findings may be listed on the report as:

• Normal
• Benign (noncancerous) breast conditions
• Benign breast conditions that increase the risk of cancer
• Carcinoma in situ
• Cancer

Benign (Noncancerous) Breast Conditions

Many different benign breast conditions can be found on a biopsy, many of which are not associated with an increased risk of breast cancer.

Some of these include:

• Fibroadenomas
• Benign breast cysts
• Fat necrosis
• Oil cysts

Benign Breast Conditions That Increase Breast Cancer Risk

Some breast conditions are associated with an increased risk of developing breast cancer in the future.

Some of these conditions include:

• Atypical hyperplasia: These are abnormal cells that have a high risk of becoming cancer, and it's considered a precancerous condition. For example, roughly 40% of people with lobular hyperplasia will develop invasive cancer within 15 years of diagnosis. There are two types.
• Atypical lobular hyperplasia: The area that produces breast milk
• Atypical ductal hyperplasia: The tubes that carry milk to the nipple
• Radial scar: Having a radial scar increases the risk of developing breast cancer.
• Adenosis: Breast adenosis is a benign condition, but those who have adenosis are about 2 times more likely to develop breast cancer.

If your biopsy shows any of these changes, your provider will recommend treatments and follow-up care.

Carcinoma In Situ

Carcinoma in situ refers to abnormal cells that appear identical to breast cancer, but have not extended outside of the first tissue location. These cancers are classified as noninvasive. Because these cells have not spread to any surrounding tissue, the removal of the cluster of abnormal cells is expected to be curative.

The two types of carcinoma in situ are:

• Ductal carcinoma in situ (DCIS)
• Lobular carcinoma in situ (LCIS)

Breast Cancer

Overall, between 20% and 30% of breast biopsies are positive for cancer. If you have cancerous cells in your sample, your biopsy report will describe the tumor in a number of ways.

Your report will list the type of breast cancer.

Some common types include :

• Ductal carcinoma: Cancers that arise in the milk ducts, ductal carcinomas are the most common type of breast cancer.
• Lobular carcinoma: This arises in the lobules of the breast and is the second most common form of breast cancer.
• Inflammatory breast cancer
• Uncommon forms of invasive breast cancer, such as medullary carcinoma, tubular carcinoma, mucinous carcinoma, and others

Your provider may request different tests from the lab, and some of these may not appear on your report.

Common pathology results include:

• Tumor grade: A description of how abnormal the tumor cells are. Higher levels of cell abnormality are generally consistent with more aggressive tumors. Tumor grade is designated with a number between 1 and 3. A grade of 1 is the least aggressive, and 3 is the most aggressive.
• Hormone receptor status: Whether or not the tumor is
• Estrogen receptor-positive (ER+)
• Progesterone receptor-positive (PR+)
• Human epidermal growth factor (HER2 status)
• Tumor margins: Surgical biopsy will have comments about the edges of the sample that was removed:
• Negative margins: The tumor was completely removed (all tumor cells are well within the margins of the surgery specimen).
• Close surgical margins: The tumor cells are completely within the biopsy sample but extend to within 1–3 millimeters of the edge.
• Positive margins: The tumor extends all the way to the edge of the biopsy sample, so it's likely that some tumor was left behind in the breast.

A fine needle biopsy cannot provide these details. And any type of breast biopsy cannot determine if breast cancer has spread to lymph nodes or distant regions of the body, and therefore cannot determine the stage of cancer.

Follow-Up

The follow-up after your breast biopsy will vary depending on the results. Your healthcare provider might discuss genetic testing with you if you have a strong family history of breast cancer—regardless of whether your biopsy is positive or negative.

Even if your biopsy is negative, your healthcare provider may recommend a repeat biopsy or other testing if they believe that cancer may have been missed.

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If the likelihood of cancer is low and your biopsy result is negative, you may be advised to follow up with routine breast screenings. Routine tests are designed for people who have an average risk of breast cancer.

If you have a benign breast condition, follow-up is usually similar to those who have negative results. With benign conditions that increase breast cancer risk, the next steps will depend on your expected risk. For those who have atypical hyperplasia, medications such as Nolvadex (tamoxifen) may be recommended. Follow-up, often with screening MRIs, may be recommended.

Carcinoma in situ is often treated with surgery. Sometimes hormone therapy is used, and chemotherapy is not typically recommended.

If your biopsy shows that you have breast cancer, you may be advised to have the tumor surgically removed. Your provider will likely recommend either a lumpectomy or mastectomy. While some people choose to seek a second opinion before scheduling surgery, the tumor should be removed as soon as possible.

Further treatments will depend on the cancer stage and may include chemotherapy, radiation therapy, hormonal therapy, and/or HER2-targeted therapy.

Summary

Breast cancer screenings may identify possible cancer that needs further diagnostic testing. A breast biopsy removes a small sample of tissue that is evaluated in the lab to determine if cancer is present or not.

There are multiple biopsy procedures and your team will help determine what is best for you. Once you know if you have breast cancer or not, your healthcare provider will guide you in your next steps.

A Word From Verywell

Breast cancer is not uncommon, and most people know of someone who has had the disease. It is normal to be nervous about a medical procedure. Knowing that you are being tested for cancer can make things even more difficult. It is important to understand that most breast biopsies are negative for cancer.

Even if cancer is found, the majority of positive biopsies will be early-stage tumors. Treatment can be curative, often with a low chance of recurrence. Even with metastatic breast cancer, treatments are improving and life expectancy is increasing.