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 study organ or tumor tissue. The sample may show unusual cells, disease, infection, or inflammation.

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

Possible Complications

Problems are rare, but no procedure is free of risk. The problems you may have will depend on the site of the FNB. Your doctor will review a list of problems, which may include:

  • Bleeding
  • Infection

Factors that may raise the risk of problems include:

  • Smoking
  • Certain medicines that increase the risk of bleeding

What to Expect

Ask your doctor if there is anything you should do before the FNB. Your doctor may ask you to:

  • Arrange for a ride home.
  • Have routine blood work.

Talk to your doctor about your medicines. You may be asked to stop taking some medicines up to 1 week before the FNB.

Just before the test, you may be asked to drink a contrast material. This drink will make images clearer on x-rays or CT scans.

Local anesthesia is often used. It will make the site numb. A medicine called a sedative may also be used to help you relax.

Your doctor may use images of the inside of your body to help guide the needle. This may be done with an ultrasound, x-ray, or CT scan.

You will be positioned for the easiest access to the site. The site where the needle will be inserted will be cleaned. Anesthesia will be applied to numb the site. You will be asked to stay still. A thin, hollow needle will then 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. After the needle is in the proper place, tissue or fluid will be withdrawn. You may feel a pinch, pressure, or nothing at all. The needle will be removed after the sample is taken. The site will be bandaged.

How long it takes will depend on the site that is sampled:

  • Simple FNB of a site that is close to the surface of the skin: a few minutes in most cases
  • Deeper FNB or one that is guided by an ultrasound or CT scan: 30-90 minutes

The amount of pain you feel depends on the part of the body having the FNB. The anesthesia and sedative will prevent pain. You may feel a pinch or pressure. If you feel pain, tell the doctor right away.

The site will be tender after the FNB. Talk to your doctor about medicine to help manage pain.

The site may bruise.

The sample will be studied by a specialist. The results are usually ready in a few days. Your doctor will talk to you about the results.

Call Your Doctor

Call your doctor if you have:

  • Signs of infection, such as fever and chills
  • Pain, redness, swelling, heat, discharge, or a red streak in the site of the needle insertion
  • Cough, shortness of breath, or chest pain
  • New or unexpected symptoms

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