Based on the results of your last mammogram, the doctor (radiologist) suggests a stereotactic core needle biopsy. In this procedure, we remove breast tissue samples with a core needle.

Before the Biopsy

A Breast Center nurse will review all prescribed and over-the-counter medicines. You may need to stop blood thinners before the biopsy. The nurse will discuss this with you. You may take Tylenol® as needed, if you do not have liver disease. The nurse will also review all allergies.

You will be awake for the biopsy. If you would like something to help you relax before the biopsy, please contact your primary doctor in advance. If you take this medicine, you must have someone drive you home. Do not drive or make important decisions until the next day.
You do not need to fast before the biopsy. If you are diabetic, follow your normal care routine.

Wear a two-piece outfit. We will ask you to undress from the waist up.
Do not wear talcum powder, lotions or deodorant on the breast and underarm area.
Your stay at the Breast Center will be about 2 hours.

During the Biopsy

You will sit in a special chair that can be positioned at different angles to allow access to the spot of your breast to be biopsied.

Your breast will be held in place by compression with paddles, like when you have a mammogram. We will take mammograms. This will help us locate the correct site for biopsy. Staff will step away behind a shield. We will ask you to hold your breath and be as still as you can.

We will clean your breast with an antiseptic. This may feel cool on your skin.

We will inject a numbing medicine (Lidocaine) into your breast. You may feel a sting.

The doctor will make a small nick in the skin of your breast and then insert the needle. You may feel pressure as this needle is placed, but should not feel any pain. If you do feel pain, let the staff know.

You will hear a whirring sound from the biopsy machine as we take the samples. We will send the samples to the lab.

After the biopsy, we will place a small titanium marker in the breast. This will mark the area of the biopsy. If you need a future surgery, this will help guide the doctor to the right spot. If you do not need surgery, the clip will stay in place. You can see it on future mammograms. There are no known risks with having the marker. Metal detectors or MRIs will not affect this marker. You will have a final mammogram to look at the placement of the marker.

We will remove the needle from your breast. You may have some light bleeding. We will apply pressure until it stops. We will cover the site with thin strips of tape (Steri-strips) and apply an ice pack for about 10 minutes.

Site Care

  • Apply ice for 20-30 minutes at least 3 times the day of the biopsy. Then, use ice as needed to reduce swelling and pain.

  • Wear a support bra, like a sports bra, for 24-48 hours.

  • You may remove the gauze bandage over the biopsy site the next day. You will have thin strips of tape or Steri-Strips over the site. These will loosen and come off on their own in about 5 days. If they are still in place after 5 days, you may gently peel them off.

  • You may shower the next morning. Do not soak in a bath or pool for 48 hours.


You may have some pain and bruising. It should go away in about a week. You may take Tylenol for the first 24 hours if you do not have liver problems. You may resume taking aspirin or ibuprofen 24 hours after the biopsy (if no signs of bleeding) or as directed by your doctor.

Blood Thinners

Ask your doctor when you can resume taking Coumadin, aspirin, or other blood thinners.


Avoid forceful arm movements and heavy lifting for the first 24 hours. You may resume your normal routine the next day or as directed by your doctor.


Your biopsy results should be ready in 3-4 working days. Your doctor or the Breast Center staff will call you with your results.

When to Call

  • Fever over 100.4 F for two readings taken 4 hours apart

  • Increased swelling, firmness, redness or warmth

  • Pus around the site

  • Heavy bleeding from the site

Who to Call

Call your doctor or the Breast Center if you have questions or concerns about your care.

UW Health Breast Center at the Clinical Sciences Center (Highland Avenue)
Monday-Friday, 8:00 am to 4:30 pm

After hours, call 608-262-2122. Ask for the radiologist on call. Give your name and number with the area code. The doctor will call you back.

UW Health Breast Center at 1 S Park Street
Monday-Friday, 8:00 am to 4:30 pm

After hours, call 608-417-6000. Ask for the radiologist on call at Meriter/Unity Point Hospital.