A breast biopsy involves removing a sample of breast tissue or cells to test them for cancer.
A doctor may recommend a biopsy if a person has an abnormal mammogram result, a lump in the breast or nearby lymph node, or changes in the nipple, such as dimpling, thickening, scaling, or crusting of the skin.
There are several ways of performing a breast biopsy.
Fine-needle aspiration biopsy
In a fine-needle aspiration biopsy (FNAB), the surgeon, pathologist, or radiologist uses a very thin needle and a syringe to withdraw, or aspirate, a few cells from a palpable lump. If a lump is palpable, it means that a person can feel it with their hand.
Alternately, the doctor may take a small amount of fluid from a fluid-filled cavity, such as a cyst.
An FNAB is a percutaneous procedure, which means that the doctor passes a needle through the skin to reach the area for sampling.
The needle used in an FNAB is usually smaller than the type of needle used in blood tests. A person usually does not need a local anesthetic.
If a person can feel a lump or potentially problematic area, the doctor can guide the needle to its target by touch.
If the target is too small or deep to feel, the doctor may perform an ultrasound and guide the needle to the right location using visuals on a screen. This is an ultrasound-guided biopsy.
In a stereotactic biopsy, mammograms taken from two angles show the exact location of the mass. Doctors also call this an image-guided stereotactic breast biopsy.
Next, a laboratory analyst examines the fluid or cells under a microscope to determine if cancer cells are present.
If the sample consists of clear fluid, there is a good chance that it came from a benign cyst, with no cancerous cells. Cloudy or bloody fluid may come from a benign or cancerous cyst.
Because doctors use such thin needles, there is the possibility of missing nearby cancerous cells. If the diagnosis is not clear, the doctor may recommend a different type of biopsy.
Core needle biopsy
In a core needle biopsy (CNB), the doctor removes small, solid samples of tissue. The needle is hollow and slightly larger in diameter than an FNAB needle.
The doctor usually uses an ultrasound or X-ray to guide the procedure. If a lump is palpable, they may guide the needle by touch.
The hollow needle withdraws cores, or small cylinders, of tissue from the mass. The needle may enter up to six times to remove several cores of tissue. The doctor may recommend a local anesthetic to numb the area.
A CNB takes longer than an FNAB, but it is less likely to miss cancerous cells, so the result is more reliable.
After a CNB, the person may experience some bruising, but no significant scarring, and they will not require stitches.
In this procedure, the doctor makes a small cut measuring less than one-quarter of an inch. They insert a hollow probe through the incision and guide it toward the mass using an MRI, ultrasound, or X-ray.
The probe has a hole in its side, and it sucks tissue into this hole, using a vacuum. The doctor can rotate the probe to collect several samples.
The person will not need stitches, and scarring is usually minimal.
Other names for this procedure include an excisional or surgical biopsy. A doctor or surgeon makes a cut measuring 1–2 inches in the breast and remove part or all of the lump for examination under a microscope.
A person usually undergoes this procedure in a hospital’s outpatient department, with either a local or general anesthetic, so that they feel no pain.
If the surgeon cannot find the lump by touch, they use X-rays to guide a thin, hollow needle to the mass. They then thread a very thin wire with a hook at the end into the hollow of the needle and attach the hook to the lump.
After removing the needle, the wire stays in place and guides the surgeon to the target area.
A surgical biopsy requires sutures, and there will be a scar. If the surgeon removes a significant amount of tissue, there may be a difference in the shape of the breast.
After a biopsy, it is common for the area to swell and bleed, making the mass seem bigger. This is normal, and the bruising and bleeding usually go away within a few days or a week.
After removing the tissue samples, the doctor may leave a tiny clip or marker, made of surgical-grade material, to identify the biopsy site. This will be visible on a mammogram.
The marker points out the exact site of the biopsy so that a doctor can find it again easily if they need to.
This is especially important if a person has chemotherapy or another systemic treatment that change the size and shape of the mass. The mass may also disappear after treatment.
During surgery, the doctor may remove the clip and surrounding tissue, even if the mass is no longer visible.
Do not use deodorant, powder, lotion, cream, or perfume on the arms or breasts on the day of the biopsy.
Before the procedure, a person should let the doctor know if they:
- have any allergies
- have taken aspirin in the previous week
- are taking anticoagulants (blood thinners), such as heparin or warfarin
- have a history of bleeding disorders
- are taking any prescription drugs, over-the-counter medications, herbs, or supplements
- have a cardiac pacemaker or any electronic device, in case the doctor plans to use an MRI
- are or may be pregnant
If there is swelling after the procedure, a cold pack may relieve discomfort. It may help to tuck the cold pack into a bra.
If the procedure involves general anesthesia, a person may need to fast, consuming no food or drink for up to 12 hours before the biopsy. The doctor will provide precise instructions.
Before leaving, find out how and when the results will arrive.
People who have had general anesthesia will go to a recovery room for observation after the procedure.
When their blood pressure, heart rate, and breathing are stable and they are mentally alert, they will be able to go home. They may still be a little drowsy and should arrange for someone else to drive them.
A person who has had local anesthesia can leave as soon as the recovery period is over.
After a biopsy, the area around any stitches must remain clean and dry. If there are no stitches, the medical team will give instructions about removing the dressing or bandage.
The biopsy area will probably be sore and tender for some days.
The following may help:
- using pain relief medication, especially after an excisional biopsy
- wearing a supportive bra
Avoid taking aspirin, as it thins the blood and increases the risk of bleeding.
The doctor may recommend avoiding strenuous physical activity for a while.
A biopsy entails very few risks. Sometimes it can cause:
- pain at the site or in the arm or neck
There is a small chance of infection with any type of biopsy. If signs of infection occur, contact the doctor.
These signs include the appearance or worsening of:
- fever or chills
- pain around the biopsy site
It is important to note that treatment is continually improving. The figure above should encourage a person to attend regular screenings.