When breast abnormalities are discovered, further evaluation of your condition is likely required to determine if the abnormality is malignant (cancerous) or benign (non-cancerous). There are two tools that may be used in this evaluation: imaging and biopsy.


The two main breast imaging techniques are mammogram and ultrasound. A third imaging technique, Magnetic Resonance Imaging (MRI), is used occasionally for diagnosis in conjunction with the other two imaging methods.


A mammogram is an x-ray image of your breast used to screen for breast cancer. Mammograms play a key role in early breast cancer detection and have aided in the overall decrease in breast cancer related deaths. During a mammogram, your breasts are compressed between two firm surfaces to spread out the breast tissue. This may be uncomfortable, with pressure lasting a few seconds, but it’s necessary to be able to get a good, clear image.

During a diagnostic mammogram, more x-rays are taken of the breast than during a screening mammogram. Extra images are taken with a focus on the area of concern, or the area that was detected to be abnormal in a screening mammogram.

These mammograms are either black-and-white pictures of the breast tissue on large sheets of film or computer images that can be can be looked at on a computer screen and saved electronically. Mammograms are read and interpreted by a radiologist (a doctor specially trained to read imaging tests).

Mammograms alone cannot prove that an abnormal area is cancer, but it is a crucial part to diagnosis. For a mammogram abnormality to be confirmed and diagnosed as breast cancer a biopsy of the suspicious tissue must occur.

Breast Ultrasound

A breast ultrasound uses sound waves to make a computer picture of the internal structure of your breast tissue. The sound waves are sent into the area of concern in your breast and then those sounds waves are echoed back. It is the echoes that are picked up by the ultrasound probe, and a computer changes the sound waves into a picture that is projected onto a screen. Radiation is not used to do this test.

This imaging test is often used to target a certain area of concern that was found on the mammogram or during a clinical exam. Ultrasound can help to identify breast changes that can be felt, but not seen on a mammogram, and it also helps differentiate between fluid-filled cysts and solid masses.

If a perceived lump is really a cyst, it is diagnosed as being benign (non-cancerous). If this is the case, as treatment your doctor may put a needle into the cyst to take out the fluid. If it is a solid mass, a biopsy will be taken for further diagnosis.

Magnetic Resonance Imaging (MRI)

MRI is an imaging test that uses a magnetic field and pulses of radio wave energy to make pictures of your breast tissue and overall breast structure. It is sometimes used to look for breast cancer in women who are known to be at high risk. It may also be used to get a closer look after breast cancer has been found, or to look for breast tumors that may be felt or symptomatic, but are not showing up on a mammogram. MRI can also be used to help guide a biopsy needle into tumors that cannot be seen on a mammogram.

Another key aspect to MRI is that it can show if your lymph nodes are enlarged, which may be a sign that they contain cancer. Lymph nodes are small bean-shaped collections of immune system tissue – they remove cell waste, germs, and other harmful substances from the body. The lymph nodes in your underarm are likely the first place that breast cancer would spread.


If you experience a change in the health of your breasts and cancer cannot be ruled out through imaging, the next step in the diagnosis of your condition will be to get a breast biopsy. A biopsy is a diagnostic procedure that definitively tells you if your experienced abnormality is cancerous or benign. Undergoing a biopsy can be scary, but remember that getting a biopsy does not mean that you have cancer. If breast cancer is found, know that it can be treated.

What is a biopsy?

A biopsy is a procedure in which breast tissue is removed from the area of suspicion as detected by a mammogram, ultra sound or MRI. The breast tissue is removed by a surgeon, or other surgical specialist, and examined under a microscope by a pathologist.  A pathologist is a doctor who specializes in identifying tissue changes that are characteristics of disease including breast cancer. The details below will help to inform you on what to expect if you have to undergo a biopsy.

Types of Biopsies

Tissue samples for biopsy can be obtained by either needle (no opening of your skin) or surgery (opening of your skin). The doctor’s choice of biopsy technique depends on such things as the nature and location of the abnormal area, your general health, and your overall preference. Details on the different types of biopsies and how they are performed are below.


Needle-localization can be done as a first step for needle biopsies and is almost always done as a first step for surgical biopsies. A needle-localized biopsy is a two-step procedure that first uses imaging to locate and mark the area of breast abnormality that can be seen on a mammogram, but may not be able to be felt. An imaging device is used to guide a thin wire with a hook on the end through a hollow needle to place the wire in or around the abnormal area. Once the wire is in the right place, the needle is removed and the wire is left in your breast tissue so that the doctor will know where the abnormal tissue is located.

Needle Biopsies

Fine Needle Aspiration Biopsy

In fine needle aspiration biopsy (FNAB), your doctor will use a very thin needle attached to a syringe to withdraw a small amount of tissue from the suspicious area. The needle used for FNAB is thinner than the ones used for blood tests and can be inserted into your breast via a very small opening.

For a FNAB, the doctor may or may not use a local anesthetic to numb the area of needle insertion. If the tissue to be biopsied can be felt, the doctor will locate the lump or suspicious area and guide the needle there. If the lump cannot be felt, but can be seen with imaging, the doctor might guide the needle to the right spot using ultrasound to watch the needle on a screen as it moves toward and into the mass. Once the needle is in place, tissue is drawn out.

Core Needle Biopsy

A core needle biopsy (CNB) is much like a fine needle aspiration biopsy (FNAB). The main difference is that in a CNB, a slightly larger, hollow needle is used to withdraw small cylinders (or cores) of tissue from the abnormal area in your breast.

A CNB is most often done with local anesthesia to numb just your breast and the area of needle insertion. The needle is put in 3 to 6 times to get the samples, or cores. This takes longer than a FNAB, but it’s more likely to give a clear result because more tissue samples are collected to be examined. Similar to FNAB, your doctor will either place the needle into the abnormal area using ultrasound or x-rays to guide the needle, or if the area is easily felt, the biopsy needle may be guided into the tumor while feeling the lump. Once the needle is in place, a core of tissue is drawn out.

Stereotactic Needle Biopsy

In a stereotactic needle biopsy, computers map the exact location of the area of suspicion using mammogram images taken from two separate angles. During the procedure, an x-ray helps find the suspicious area and the tissue to be removed. Stereotactic biopsy involves compression of the breast between two paddles and then an x-ray is taken.  To be able to get images during the procedure, you will need to lie on your stomach on a special table that has an opening for your breast.

Prior to the procedure, your doctor will numb your breast and area of needle insertion with local anesthetic so that you will not feel pain. A small nick is made in your skin, and a thin needle is inserted through the nick. The needle is then guided to the biopsy area via the x-ray images, and the needle is used to remove several tiny samples of breast tissue.

Things to keep in mind about needle biopsies:
  • Needle biopsies can sometimes miss cancer if the needle does not get a tissue sample from the abnormal area of concern. If this happens, your results would be false-negative and your diagnosis may be delayed. If the biopsy does not give a clear diagnosis, or your doctor still has concerns, a second biopsy will need to be done.
  • Needle biopsies cannot always tell you all of the information about the area of concern. For example a biopsy cannot tell you how big the area or tumor is, or if a cancerous tumor is invasive. Sometimes a surgical biopsy will be needed to obtain all details.
  • Needle biopsies are common and safe procedures, but although rare, they do have some risk. Aside from failure to remove the right tissue as noted above, biopsies can sometimes cause bleeding and infection.

Surgical Biopsies

Your doctor will most often try to figure out the cause of a breast abnormality by doing a needle biopsy, but in some cases a surgical (open) biopsy may be needed. A surgical biopsy is more involved than a needle biopsy – stitches are often needed, and it will leave a scar. A surgical biopsy is done by cutting the breast to take out all or part of the area of suspicion so that it can be examined under a microscope.

There are 2 types of surgical biopsies:

  • Incisional biopsy: An incisional biopsy removes only part of the suspicious area, which is enough to make a diagnosis.
  • Excisional biopsy: An excisional biopsy removes the entire tumor or abnormal area, with or without trying to take out an edge of normal breast tissue – this depends on the reason for the excisional biopsy.

For a surgical biopsy, you will be under either local or general anesthesia. You may also be given medicine to make you sleepy.

Prior to the biopsy, needle localization will most likely be done (as detailed above in Needle-Localized Biopsy).   A radiologist will locate your abnormal breast tissue via a mammogram just prior to surgery and will insert a fine wire into the suspicious area. You will then go into the operating room where the surgeon locates the previously inserted wire and surgically removes the targeted area.  The more precisely the wire is placed, the less tissue that needs to be removed.

Sometimes the surgeon will be able to feel the lump during surgery.  In other cases, especially where the mammogram shows only microcalcifications, the abnormality can be neither seen nor felt.  To make sure the biopsy tissue does in fact contains the abnormal area, your breast may be x-rayed in the midst of the surgery.

What can I expect prior to a biopsy?

Prior to a biopsy you can expect to be given details about the days leading up to, and the day of, the biopsy. You will get details including the location of the procedure, timing, and any requirements that need to be taken care of beforehand.

Biopsies are generally done within a hospital’s “outpatient” or “same day surgery” department. A biopsy being an outpatient procedure means that you would not have to stay overnight.  It is common for you to be in the biopsy room for less than an hour. Depending on the time of your biopsy, your doctor or nurse will give you instructions on when and if you may eat or drink beforehand. Before the biopsy, follow these and other guidelines that you are given:

  • Tell your doctor what medications you take (including aspirin and ibuprofen), and ask if and when you should stop taking them.
  • Wear a top that is easily removed and a comfortable bra.
  • Bathe before the procedure.
  • Do not wear perfume, deodorant, lotion, powder, or any other substances on your skin.
  • Try to empty your bladder before the procedure to help you be more comfortable throughout your procedure.

At the hospital, or a few days prior, you may undergo routine testing such as blood and urine tests, a chest x-ray and an EKG (electrocardiogram), which records the activity of your heart.  These tests give the doctor all of the details about your general health to ensure you have everything you need prior to the biopsy.

Before the biopsy you will also be asked to sign a paper called an informed consent form.  An informed consent document explains the biopsy procedure and gives your doctor permission to perform the procedure.  If you do not understand this form be sure to ask the doctor or nurse to explain it to you in detail.

If you like, bring a family member with you to the appointment. Though they may not be allowed in the biopsy room, they can offer support. A technologist will stay with you throughout the procedure.

What happens after a biopsy?

After the biopsy, you will be taken to your room or the outpatient care area.  Most women have very little discomfort after a biopsy.  If you have general anesthesia or IV sedation, you will probably be sleepy and want to rest.  Depending on how you feel, you will be ready to go home one to two hours after the biopsy.

It is best for a family member or friend to take you home. Before leaving the hospital, you will get instructions on how to take care of the incision. Be sure to ask your doctor or nurse how you will find out about your results and who will explain them to you.

Plan to take it easy for at least 24 hours. You should be able to return to your normal routine within a day or two. However, for the next week or so your breast may be sore and slightly bruised. All biopsies can cause bleeding and swelling. This can make it seem like the breast lump is bigger after the biopsy. This is usually nothing to worry about and the bleeding and bruising will go away quickly in most cases. Also, the incision may feel firm for 3-4 months.

Will a biopsy change the shape of my breasts?

Whether or not a surgical biopsy will change the shape of your breast depends on the size of the lump and where it is located in the breast as well as how much margin of healthy tissue the surgeon decides to remove.  You should talk with your doctor beforehand so you understand just how extensive the surgery will be and your cosmetic result.