1. What is a breast biopsy?
2. Core biopsy
3. Fine needle aspiration (FNA)
4. Other types of breast biopsy
5. Inserting a metal marker
6. Breast biopsy results

1. What is a breast biopsy?

A biopsy involves removing a small sample of breast cells or breast tissue. The sample is sent to the laboratory where it’s looked at under a microscope. 

You may have a breast biopsy if you have been referred to a breast clinic to investigate a breast change. 

Most people who have a breast biopsy do not have breast cancer. They may have normal breast changes or a benign (not cancer) condition.  

There are different types of breast biopsy. Most people have a core biopsy, but you may be offered a fine needle aspiration (FNA) or another procedure. 

2. Core biopsy

What is a core biopsy?

A core biopsy (also called core needle biopsy) uses a hollow needle to get a sample of breast tissue. 

Because tissue is taken rather than cells, it gives more detailed information. Several tissue samples may be taken at the same time. 

How a core biopsy is done

After local anaesthetic is given to numb the area, a small cut is made in the skin. 

Samples of tissue are then taken with the biopsy needle. 

Sometimes you’ll be asked to lie on your front while this is done. 

Stereotactic core biopsy

If the area of concern can only be seen on a mammogram, you may have a stereotactic core biopsy. 

A sample of tissue is taken using a needle biopsy device connected to a mammogram machine and linked to a computer. This helps locate the exact position of the area to biopsy. 

Images of the breast are taken from two different angles to help guide the needle to the precise location.

You’ll be given a local anaesthetic and will be in a sitting position or lying down on a specially designed examination couch. 

It may feel a little uncomfortable as the mammogram plates are pressed onto the breast throughout. 

After your biopsy

A small dressing or plaster will usually be applied. You’ll be asked to keep this on for a day or so afterwards. 

Sometimes very thin strips of adhesive tape are used to help the edges of the wound to close. 

Once the local anaesthetic wears off, your breast may ache and may be bruised for the next few days or weeks. 

You can take pain relief if the area is tender or painful. You’ll be given more information about this before you leave the clinic. 

3. Fine needle aspiration (FNA)

A fine needle aspiration or FNA uses a fine needle and syringe to take a sample of cells. 

Occasionally, local anaesthetic is used first to numb the area. 

You may be asked to wear a plaster for a few hours over the site where the needle has been inserted. 

4. Other types of breast biopsy 

Punch biopsy

A punch biopsy may be done when there’s a change to the skin of the breast or nipple. 

It involves taking a very small cylindrical piece of tissue from the changed area. 

You’ll be given a local anaesthetic before a tiny cutting device is used to take the sample. You’ll usually be asked to wear a small dressing or plaster afterwards. 

Vacuum assisted biopsy

If a previous biopsy has not given a definite result and more breast tissue is needed to make a diagnosis, or if the area of concern is difficult to target, you may be offered a vacuum assisted biopsy. 

This procedure takes a little longer than a core biopsy. 

After an injection of local anaesthetic, a small cut is made in the skin. A special needle connected to a vacuum device is placed through this. 

Using a mammogram or ultrasound as a guide, breast tissue is sucked through the needle by the vacuum into a collecting chamber. This means several samples of tissue can be collected without removing the needle. 

Sometimes this procedure is used as an alternative to surgery to remove a whole area of breast tissue. This is called a vacuum assisted excision biopsy. 

5. Inserting a metal marker 

Sometimes, if the area of concern is small or difficult to see on a mammogram or ultrasound, a small metal clip (or marker) is placed in the breast where the biopsy has been taken. 

This is so the area can be found again if a further biopsy or surgery is necessary. 

If another procedure is not needed, the clip can be safely left in the breast.

The marker clip is usually made of titanium, the same metal used for joint replacement surgery. It will not set off alarms at airports. 

Most clips are now suitable for having an MRI scan. However, if you need an MRI in the future, tell your doctor or radiographer that you have a metal clip.

6. Breast biopsy results 

The breast clinic will let you know how and when you’ll get your results. 

Core biopsy results

You may hear your results described as a letter and a number. ‘B’ stands for ‘biopsy’.

Core biopsy results may be described as:

  • B1: normal breast tissue 
  • B2: benign (not cancer) 
  • B3: abnormal or uncertain but probably benign 
  • B4: suspicious and possibly cancer 
  • B5: cancer

Fine needle aspiration results

You may hear your results described as a letter and a number. ‘C’ stands for ‘cytology’, which means the study of cells. 

FNA results may be described as:

  • C1: inadequate sample (not enough cells for diagnosis) 
  • C2: benign (not cancer) 
  • C3: unusual, abnormal or uncertain but probably benign 
  • C4: suspicious and possibly cancer 
  • C5: cancer

Understanding your results 

Your specialist team will use the result to help them decide if you need more tests or treatments. 

They are usually needed for a result showing B3/B4/B5 or C3/C4/C5, or where the findings of all the tests do not agree.

Waiting for biopsy results

Waiting for breast biopsy results can be a very worrying time. 

If you’re anxious about your results or would like to talk to someone about any concerns you can call our free Helpline on 0808 800 6000. 

Last reviewed: November 2022
Next planned review begins November 2024

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