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Background: Mammograms and other imaging techniques cannot prove that an abnormal area is cancer. If an area continues to look suspicious, a biopsy will be recommended. A biopsy is the definitive way to know whether a mass is cancer or not. 

A biopsy is the removal of part of the lump or suspicious area by a very thin needle or by surgery. The sample is then examined under a microscope.

  • The procedure permits a medical doctor known as a pathologist to look at cells from your body and determine whether they are cancerous (malignant) or not cancerous (benign). 
  • 4 out of 5 biopsies do not find a malignancy.
    • Usually the breast change is a fibrocystic change or a benign breast tumor.
    • A fibrocystic change is a benign change in breast tissue.This change often happens just before a menstrual period is about to begin. Lumps and areas of thickening caused by fibrocystic changes are almost always harmless.
    • A benign breast tumor is a non-cancerous area where breast cells have grown abnormally and rapidly, often forming a lump. Unlike cysts, which are filled with fluid, tumors are solid. Benign breast tumors are sometimes uncomfortable, but they
  • Initial biopsies are usually performed by a medical doctor known as a radiation oncologist.
  • A biopsy starts with the removal of cells or tissues from the body for examination by a pathologist. The pathologist may study the tissue under a microscope or perform other tests on the cells or tissue. If the biopsy shows that cancer is present, the pathologist's findings become a primary basis for helping to determine the best treatment.
  • There are a variety of biopsy procedures. The method that will be recommended in any particular situation depends on the size and location of the area of interest. The most common types of biopsies are: 
    • Incisional biopsy, in which only a sample of tissue is removed.
    • Excisional biopsy, in which an entire lump or suspicious area is removed. 
    • Needle biopsy, in which a sample of tissue or fluid is removed with a needle through the skin. 
      • When a wide needle is used, the procedure is called a core biopsy. 
      • When a thin needle is used, the procedure is called a fine-needle aspiration biopsy.

Before agreeing to a biopsy: 

  • Understand the type of biopsy the doctor recommends and what is involved. Ask questions such as: 
    • Does the doctor plan to use a pain killing anesthetic during the procedure?
    • If not, why not?
    • If so, ask:
      • Which anesthetic plan the doctor plans to use. 
      • What the alternatives are to the plan he or she is suggesting
      • The circumstances under which he or she may decide to administer another drug during the course of the procedure. 
      • For additional questions to ask, click here.
    • Check to see that the consent form you will be asked to sign before the procedure describes what you think you have agreed to, including the identity of the person you think will be performing the procedure.
    • Check to see that the person who will perform the biopsy is covered by your insurance. Do not assume that just because the facility is covered, the doctor is also covered by your insurance and vice versa.
  • If the biopsy reveals that the sample is cancer, a common next step is to remove the cancer with surgery. 
    • Discuss whether to proceed to surgery at the same time as the biopsy, and if so, what kind of surgery. For information about one or two steps, click here.  (For questions to ask before agreeing to surgery, click here.)
    • If you agree to a one step procedure of biopsy and surgery, check with your insurance company to determine whether a one step procedure is covered. It is not unusual for insurance companies to require a second opinion before covering surgery.  
  • Especially if you will have a local anesthetic and will be awake during the biopsy, ask the doctor not to tell you his or her preliminary thoughts about the results. The pathologist's report is necessary to determine the results with certainty.
  • Check your health insurance to see if it is covered. (Biopsies are generally covered by health insurance).
    • If it is covered, how much will you have to pay?
    • If the biopsy is not covered, what is the cost?  See Uninsured. (link to T49 ) Keep in mind that all medical bills are negotiable. To learn how to negotiate a medical bill, click here
  • Look at the section of this article which discusses the steps to take to prepare for a biopsy.

After a biopsy, a doctor known as a pathologist will examine the sample and prepare a report of the results. The report is known as a pathology report. 

  • The pathology report will be sent to your gynecologist or other referring doctor. That doctor will review the pathology report with you.
  • We suggest you ask for a copy of the report so you can discuss it in a meaningful way. 
    • You are entitled to receive a copy of the pathology report. 
    • Having a copy on hand means that it will be available without delay when other doctors need it.
    • By law, the report is supposed to be written so that lay people with no medical knowledge can understand it.
  • Particularly ask whether the report contains any uncertainty. An accurate diagnosis is key to identifying the best treatment.
  • For assistance reading a pathology report, click here.   If you have difficulty understanding the report, call the American Cancer Society for a copy of Dictionary of Breast Cancer Terms. Call 800.ACS.2345.
  • If there are any questions, consider getting a second pathology opinion. For example, from a pathologist at a major academic cancer center or a National Cancer Institute certified comprehensive cancer center. You can locate such a center by clicking here offsite link.

If a biopsy shows that you have cancer, before choosing a treatment option, consider getting a second opinion from a radiologist or surgical oncologist who is not connected with the originating doctor or facility. If you decide to get a second opinion: 

  • Find out from the doctor that will provide the second opinion what documentation is needed. Generally this will be the original biopsy records rather than a copy.
  • Check to find out whether the second opinion will be covered by your health insurance. If so, what portion will you have to pay? If insurance does not cover it, find out how much the second opinion will cost.

For additional information, see:

When you are ready to consider treatments, we suggest that you read: How To Choose A Treatment.  Also see: Breast Cancer Surgery

Types Of Biopsy Procedures

Each type of biopsy has pros and cons. The choice of which type to use depends on your situation. Some of the things your doctor will consider include how suspicious the tumor looks, how large it is, where it is in the breast, how many tumors are present, other medical problems you may have, and your personal preferences. You might want to talk to your doctor about the pros and cons of different biopsy types.

Fine needle aspiration biopsy

In fine needle aspiration biopsy (FNAB), the doctor (a pathologist, radiologist, or surgeon) uses a very thin needle attached to a syringe to withdraw (aspirate) a small amount of tissue from a suspicious area. This tissue is then looked at under a microscope. The needle used for FNAB is thinner than the ones used for blood tests.

If the area to be biopsied can be felt, the needle can be guided into the area of the breast change while the doctor is feeling (palpating) it. If the lump can't be felt easily, the doctor might use ultrasound to watch the needle on a screen as it moves toward and into the mass. Or the doctor may use a method called stereotactic needle biopsy to guide the needle. For stereotactic needle biopsy, computers map the exact location of the mass using mammograms taken from 2 angles. This helps the doctor guide the needle to the right spot.

The doctor may or may not use a numbing medicine (local anesthetic). Because such a thin needle is used for the biopsy, getting the anesthetic may hurt more than the biopsy itself.

Once the needle is in place, fluid is drawn out. If the fluid is clear, the lump is most likely a benign cyst. Bloody or cloudy fluid can mean either a benign cyst or, very rarely, a cancer. If the lump is solid, small pieces of tissue are drawn out. A pathologist (a doctor who is expert in diagnosing disease from tissue samples) will look at the biopsy tissue or fluid under a microscope to find out if it is cancer.

A fine needle aspiration biopsy can sometimes miss a cancer if the needle does not get a tissue sample from the area of cancer cells. If it does not give a clear diagnosis, or your doctor is still suspicious, a second biopsy or a different type of biopsy should be done.

If you are still having menstrual periods (that is, if you are premenopausal), you most likely know that breast lumpiness can come and go each month with your menstrual cycle. But if you have a lump that doesn't go away, the doctor may want to do a FNAB to see if it is a cyst (a fluid-filled sac) or a solid growth (mass or tumor). If an aspiration is done and the lump goes away after it is drained, it usually means it was a cyst, not cancer. Again, most breast lumps are not cancer.

Core needle biopsy

A core needle biopsy (CNB) is much like an FNAB. A slightly larger, hollow needle is used to withdraw small cylinders (or cores) of tissue from the abnormal area in the breast. CNB is most often done with local anesthesia (you are awake but your breast is numbed) in the doctor's office. The needle is put in 3 to 6 times to get the samples, or cores. This is more invasive and takes longer than an FNAB, but it is more likely to give a definite result because more tissue is taken to be looked at. CNB can cause some bruising, but usually does not leave scars inside or outside the breast.

The doctor doing the FNAB or CNB usually guides the needle into the abnormal area while feeling (palpating) the lump. If the abnormal area is too small to be felt, a radiologist or other doctor may use needle placement, a stereotactic instrument, or ultrasound to guide the needle to the target area.

Stereotactic core needle biopsy

A stereotactic core needle biopsy uses x-ray equipment and a computer to analyze the pictures (x-ray views). The computer then pinpoints exactly where in the abnormal area to place the needle tip. This type is often used to biopsy microcalcifications (calcium deposits).

Larger core biopsies

Large core biopsies that use stereotactic methods can be done to remove even more tissue than a core biopsy.

Vacuum-assisted core biopsy

The Mammotome ' is one type of vacuum-assisted core biopsy (VACB). For this procedure the skin is numbed and a small cut (about ' inch) is made. A hollow probe is put into the incision and then into the abnormal area of breast tissue. A cylinder of tissue is then suctioned in through a hole in the side of the probe, and a rotating knife within the probe cuts the tissue sample from the rest of the breast.

There are 2 other types of vacuum-assisted core biopsy systems:

  • ATEC
  • MIBB (short for minimally invasive breast biopsy)

Both of these methods also allow tissue to be removed through a single small opening. And both methods are able to remove more tissue than a standard core biopsy. No stitches are needed and there is very little scarring. Vacuum-assisted core biopsies are done in outpatient settings.

Rotating circular "cookie-cutter" knife

The ABBI method (short for Advanced Breast Biopsy Instrument) uses a probe with a rotating circular knife and thin wire to remove a larger cylinder of abnormal tissue. ABBI is used with x-ray guidance (stereotactic imaging), and can sometimes be used to remove an entire mass. It is slightly less invasive than a surgical biopsy. A few stitches may be needed afterward.

Magnetic resonance imaging (MRI) guidance

In some centers, the biopsy is guided by an MRI, which uses computer analysis to find the tumor, plot its coordinates, and help aim the needle or biopsy device into the tumor. This is helpful for women with a suspicious area that can only be seen by MRI. One of the vacuum-assisted core biopsy systems, the ATEC, is designed so that it can be used with an MRI.

Ultrasound-guided biopsy

Ultrasound-guided biopsy uses an instrument that sends out sound waves and a computer to make pictures of the breast abnormality. A doctor can use this test to guide a needle into very small tumors or cysts.

Surgical (excisional) biopsy

A surgical biopsy is used to remove all or part of the lump so it can be looked at under the microscope. An excisional biopsy removes the entire mass or abnormal area, as well as a surrounding margin of normal-looking breast tissue. In rare cases, this type of biopsy can be done in the doctor's office, but it is more often done in the hospital's outpatient department under a local anesthesia (where you are awake, but your breast is numb). You may also be given medicine to make you drowsy.

During an excisional breast biopsy the surgeon may use a procedure calledwire localization if there is a small lump that is hard to find by touch or if an area looks suspicious on the x-ray but cannot be felt. After the area is numbed with local anesthetic, a thin, hollow needle is put into the breast and x-ray views are used to guide the needle to the suspicious area. A thin wire is put in through the center of the needle. A small hook at the end of the wire keeps it in place. The hollow needle is then removed, and the surgeon uses the wire to guide him to the abnormal area to be removed.

If a benign condition is diagnosed, no other treatment is needed. If the diagnosis is cancer, there is time for you to learn about the disease and talk about treatment options with your cancer care team, friends, and family. There is no need to rush into treatment. You may want to get a second opinion before deciding on what treatment is best for you.

Questions To Ask Before Having A Biopsy

Here are some questions you might want to ask your doctor before having a biopsy done:

  • What type of biopsy do you recommend? Why?
  • How does the size of my breast affect the procedure?
  • Where will you do the biopsy?
  • What exactly will you do?
  • How long will it take?
  • Will I be awake or asleep during the biopsy?
  • Can I drive home afterward or will I need someone to drive me?
  • If you are using a wire to help find the abnormal area (localize), will you check its placement by ultrasound or with a mammogram?
  • Can you draw pictures showing me the size of the incision and the size of the tissue you will remove?
  • Will there be a hole there? Will it show afterward?
  • Where will the scar be? What will it look like?
  • How soon will I know the results?
  • Should I call you or will you call me with the results?
  • Will you or someone else explain the biopsy results to me?
  • When can I take off the bandage?
  • When can I take a shower?
  • Will there be stitches? Will they dissolve or do I need to come back to the office and have them removed?
  • Will there be bruising or changes in color of the skin?
  • Will there be a scar?
  • When can I go back to work? Will I be tired?
  • Will my activities be limited? Can I lift things? Care for my children?

Does A Biopsy Or Surgery Cause Cancer To Spread?

In nearly all cases, surgery does not cause cancer to spread. There are some important exceptions, such as tumors in the eyes or testicles. Doctors who are experienced in taking biopsies of cancers and treating them with surgery know how to avoid the danger in these situations.

The chances of a needle biopsy causing a cancer to spread are very low. In the past, larger needles were used for biopsies, and the chance of spread was higher.

One common myth about cancer is that it will spread if it is exposed to air during surgery. Some people may believe this because they often feel worse after the operation than they did before. It is normal to feel this way when you start to recover from any surgery. And sometimes, no one knows that the cancer has spread until it is seen during surgery. Because of this, some people may link surgery with widespread cancer. But cancer does not spread because it has been exposed to air. If you put off or refuse surgery because of this myth, you may be harming yourself by passing up effective treatment.

Biopsy And Surgery: Two-step Or One-Step?

If your biopsy results show cancer and you need to have more surgery to remove it, the surgery is almost always done later, after the biopsy. This is called a two-step procedure. But sometimes a one-step procedure can be done in which the biopsy and surgery are done during the same operation. If you have a one-step procedure, you will want to know all of your treatment options beforehand because you must make important choices before the one-step procedure begins.

The two-step procedure

For many years, a one-step procedure was the only choice. Today, most women and their health care team prefer to schedule further surgery, if needed, after the biopsy. Many studies have shown that the emotional burden of breast cancer is easier to bear if the biopsy and treatment are done at different times.

In the two-step approach, the biopsy is most often done on an outpatient basis. Local anesthesia is used (the breast is numbed), so you stay awake. Many women choose local anesthesia plus a sedative (medicine to make you sleepy) given through a vein. The sedative helps make you feel sleepy and calms any nervous or anxious feelings you may have during the procedure. The biopsy can take about an hour. You can go home an hour or so later, when the sedative wears off.

With the two-step procedure, if the diagnosis is breast cancer, you usually don't have to decide on treatment right away. With most breast cancers, there is no harm to your health in waiting a few weeks. This gives you time to talk about your treatment options with your doctors, family, and friends, and then decide what's best for you.

How To Prepare For A Biopsy

Before having a biopsy, it is advisable to:

  • Pause taking blood thinning medications for a few days before the biopsy because of an increased risk of persistent bleeding after a biopsy.
  • Ask about when to start taking an oral antibiotic. Antibiotics are often given to protect against potential infection after a biopsy. Antibiotics are generally started the day before, or the day of, a biopsy.
  • Ask any and all questions you may have about the biopsy. (For suggested questions, see the section of this document about Questions To Ask). 
  • Check to see that the consent form you will be asked to sign before the procedure describes what you think you have agreed to, including the identity of the person you think will be performing the procedure.
  • Check to see that the person who will perform the biopsy is covered by your insurance. Do not assume that just because the facility is covered, the doctor is also covered by your insurance.
  • Consider whether to get a second opinion from a radiologist or surgical oncologist who is not connected with the originating doctor or facility. This is particularly the case if the recommendation is a surgical biopsy. If you decide to get a second opinion:
    • Find out from the doctor that will provide the second opinion what documentation is needed. Generally this will be the original biopsy records rather than a copy.
    • Check to find out whether the second opinion will be covered by your health insurance. If so, what portion will you have to pay? If insurance does not cover it, find out how much the second opinion will cost. (The document in "To Learn More" helps figure out how to get uninsured treatments.)