Definition & Overview

A biopsy is the process of removing a sample tissue from a suspected cancerous growth. It is usually performed by inserting a needle through the skin and into the growth, hence the term “percutaneous”. One of the most common percutaneous biopsy techniques is called the core needle biopsy, which can be performed without the use of imaging technology, such as an ultrasound.

Percutaneous core needle biopsy without imaging can only be performed if the suspected growth can be felt or located through a physical examination. If not, imaging will be needed to ensure that the tissue obtained is from the suspected growth.

A core needle biopsy is usually performed as a diagnostic procedure for suspected breast cancer. It is similar to a fine needle aspiration (FNA) technique, but with a bigger needle. The needle used in an FNA is smaller than the needle used to draw blood. In a core needle biopsy, the needle is almost similar in size to those used in drawing blood from the veins.

Who Should Undergo & Expected Results

Breast cancer is a major concern for women all around the world. In fact, in the United States, the American Cancer Society estimates that 1 in 8 women will be affected by the disease.

Fortunately, breast cancer can be treated. If the disease is found during its earlier stages, treatment is very effective. Patients who receive treatment for stage 1 breast cancer have a very high chance of surviving the disease.

The key to detecting breast cancer in its early stages is to undergo a screening test. This includes a mammogram, clinical breast exam, and a magnetic resonance imaging (MRI) test. These tests can determine a suspected abnormal growth in the breast, but they cannot confirm if the growth is cancerous or not. Thus, once an abnormal growth is detected, the patient will need to undergo a biopsy to determine the exact condition.

Today, percutaneous core needle biopsy is one of the most common techniques used. It is minimally invasive and performed on an outpatient basis. The sample tissue obtained is forwarded to a laboratory to determine if it is positive or negative for cancer.

The pathologist then forwards the results of the biopsy to the doctor for a diagnosis. Should the results be positive, the doctor will likely recommend a cancer specialist (oncologist) for treatment.

How Does the Procedure Work?

As described above, a biopsy will only be performed if a suspicious growth in the breast is detected through a breast screening procedure. The attending doctor will describe the different biopsy techniques, but most will recommend an FNA or a core needle biopsy, as these are minimally invasive.

A core needle biopsy is performed using an anaesthetic to numb the breast so that the patient will not feel any pain during the procedure. In most cases, preparation for the procedure is not required. However, if the patient is undergoing treatment for other medical concerns, the doctor needs to be aware of the medications being used, especially blood thinners.

Prior to the procedure, the doctor will perform a physical examination of the breast to locate the abnormal growth. The area will then be marked and the patient is asked to lie on a table.

An anaesthetic is then administered to numb the area before performing the actual procedure. In most cases, a pathologist will require a good amount of sample tissue to test. Thus, the doctor performing the core needle biopsy will need to insert the needle at least three times to obtain enough sample tissue.

The entire procedure should take less than an hour to complete. The patient will be given pain relievers should any pain arise while they are resting at home. After a day’s rest, the patient will be able to resume regular daily activities while waiting for the results of the biopsy.

Possible Risks and Complications

Even though a core needle biopsy is considered to be minimally invasive, there are still risks and possibilities of complications associated with the procedure. These include:

  • Bruising at the affected area
  • Bleeding at the injection site
  • Infections

There is also a risk of a false negative result. This means that the result of the biopsy could show a negative result for cancer cells, but the result may be erroneous. However, this rarely happens.


  • Issa J Dahabreh, MD, MS, Lisa Susan Wieland, PhD, Gaelen P Adam, MLIS, Christopher Halladay, BA, MS,Joseph Lau, MD, and Thomas A Trikalinos, MD. “Core Needle and Open Surgical Biopsy for Diagnosis of Breast Lesions;

  • Marek Boba, Urszula Kołtun, Barbara Bobek-Billewicz, Ewa Chmielik, Bartosz Eksner, Tomasz Olejnik; “False-negative results of breast core needle biopsies – retrospective analysis of 988 biopsies”. J.Tayloy Whaley MD; “Core Needle Biopsy”;

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