by Scholten A

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A biopsy is a procedure to remove a tissue sample. In a fine needle biopsy (FNB), fluid and cells are removed with a thin, hollow needle.

Fine Needle Biopsy of the Breast
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Reasons for Procedure

FNB is used to look at the tissue of an organ or tumor. The sample may show unusual cells, disease, infection, or inflammation.

It may also be done to find out how certain treatments are working.

Possible Complications

Problems are rare, but all procedures have some risk. The doctor will go over some problems that could happen, such as:

  • Excess bleeding
  • Problems from anesthesia, such as wheezing or sore throat
  • Infection

Things that may raise the risk of problems are:

  • Smoking
  • Drinking
  • Chronic diseases, such as diabetes or obesity

What to Expect

Prior to Procedure

The medical team may meet with you to talk about:

  • Anesthesia options
  • Any allergies you may have
  • Current medicines, herbs, and supplements that you take and whether you need to stop taking them before the procedure
  • Fasting before the test, such as avoiding food or drink after midnight the night before
  • Whether you need a ride to and from the procedure


The doctor may give:

  • A sedative—you will feel relaxed
  • Local anesthesia—the area will be numbed

Description of the Procedure

You may be asked to drink contrast material. This will make images clearer.

Images may be taken to help guide the needle. This may be done with an ultrasound, x-ray, or CT scan .

You will be put in a position that helps the doctor see the site. You will be asked to stay still. A thin, hollow needle will be inserted through the skin to the site. The needle may need to be inserted more than once. The images may be checked to make sure the needle is in the right place. Tissue or fluid will be drawn through the needle. The needle will be removed after the sample is taken. The site will be bandaged. The sample will be sent to a lab.

How Long Will It Take?

How long it takes will depend on the site:

  • Simple FNB of a site that is close to the surface of the skin may take a few minutes
  • Deeper FNB or one that is guided by an ultrasound or CT scan may take 30 to 90 minutes

Will It Hurt?

Mild pain is common in the first 2 days. Medicine and home care can help.

Average Hospital Stay

Most people can go home the same day. If you have any problems, you may need to stay longer.

Post-procedure Care

At the Care Center

You will be able to go home when the anesthesia wears off.

At Home

Activity should be limited for the rest of the day. It will take two days for the discomfort to go away.

Call Your Doctor

Call your doctor if you are not getting better or you have:

  • Signs of infection, such as fever and chills
  • Pain, redness, swelling, heat, discharge, or a red streak at the site of the needle insertion
  • New or unexpected symptoms

If you think you have an emergency, call for medical help right away.


Family Doctor—American Academy of Family Physicians 

National Cancer Institute 


Canadian Cancer Society 

Health Canada 


Biopsy for breast cancer diagnosis: Fine needle aspiration biopsy. UCSF Health website. Available at: Accessed January 13, 2021.

Fine needle aspiration biopsy. American Academy of Otolaryngology—Head and Neck Surgery website. Available at: Accessed January 13, 2021.

Palpable mass evaluation in women. EBSCO DynaMed website. Available at: Accessed January 13, 2021.

Tani E, Fuentes-Martinez N, et. al. A review of the use of fine-needle aspiration biopsy of mammary tumors for diagnosis and research. Acta Cytologica 2017;61:305-315.

Revision Information

  • Reviewer: EBSCO Medical Review Board Marcin Chwistek, MD
  • Review Date: 02/2021
  • Update Date: 01/13/2021