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Fine Needle Aspiration and Core Biopsy

Fine needle aspiration (FNA) and core-needle biopsy are two types of breast biopsy. A breast biopsy is a procedure that involves passing a thin needle through the skin to sample fluid or tissue from a cyst or solid mass in the breast. The sample is then sent to a pathology laboratory for analysis.

Why might a fine needle aspiration or core biopsy be required?

A breast biopsy is often performed when a suspicious lump is found in the breast during imaging tests such as an x-ray, ultrasound or mammography. It is a procedure that involves passing a thin needle through the skin to sample fluid or tissue from a cyst or solid mass in the breast. The sample is then sent to a pathology laboratory for analysis. Fine needle aspiration (FNA) and core-needle biopsy are two types of breast biopsy.

Biopsies are often performed when a suspicious lump is found, for example a breast lump or enlarged lymph node, or if an abnormality is detected during an imaging test such as x-ray, ultrasound or mammography. Fine needle aspiration and core-needle biopsy are both relatively non-invasive and are both less painful and quicker than a surgical biopsy.

How are the procedures performed?

Fine-needle aspiration (FNA)

This form of breast biopsy is generally used when it is assumed the lump in question is filled with fluid. During the procedure you will undress from the waist up, lie on your back and place your hand above your head on a pillow. The doctor will then insert a needle through the skin into the lesion. The lump should collapse once the fluid inside has been drawn and discarded. In some cases your doctor will carry out this procedure using an ultrasound.  The picture of the inside of the breast created by the sound waves will help the doctor penetrate the exact lesion site. An RDA will be present to assist with the procedure.

Core-needle biopsy

During a Core needle biopsy a small amount of suspicious tissue is removed from the breast using a large “core” (meaning “hollow”) needle. It is generally carried out whilst a patient is under local anaesthetic so the breast is numbed. As with a Fine Needle Aspiration the radiologist or surgeon performing the core biopsy may use specialised imaging equipment to ensure the needle penetrates the lesion site. During the procedure, the doctor may leave a small marker inside the breast to highlight the biopsy location. This makes it easier for the surgeon to locate the lesion if surgery is required. A mammogram will be performed post marker insertion.  An RDA will be present to assist with the procedure.


Risks associated with breast Fine Needle Aspiration (FNA) and core-needle biopsy:


  • Slight bleeding and bruising.

Extremely rare

  • Breast implant perforation if the lesion is close to the implant- highly unlikely if an ultrasound is used to guide the needle.
  • Infection- rare as they are both clean and sterile procedures carried out using skin antiseptic and disposable one-use needles.

It is worth noting breast FNA and core-needle biopsy tests are not 100% accurate. The results must always be interpreted by the doctors caring for you in the context of their medical examination, findings of your breast imaging (mammogram and/or ultrasound) and the pathology results of the tissue (cells) or fluid sample. This is called the “triple test”.


 You can eat, drink and take medications as normal before a breast Fine Needle Aspiration (FNA) or core-needle biopsy. However if you are taking any blood thinning medicines you may need to stop them before the test. Your doctor or nurse will tell you when to stop.


When the breast Fine Needle Aspiration (FNA) or core-needle biopsy is complete the sample will be sent to a pathologist for examination. The pathologist will look for abnormal or cancerous cells. The pathology report can take up to two weeks to complete. It indicates whether the suspicious area is cancerous and provides a full picture of your situation.

Breast Clinic

The Breast Unit comprises a multidisciplinary team that enables surgeons to work in partnership with their colleagues in imaging and pathology to ensure a smooth and informed process for patients.

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Patient information

Our Hospital is renowned for providing exemplary levels of care across more than 90 services. From orthopaedics, to urology, our private GP practice and Urgent Care Clinic, our services are led by some of London’s leading Consultants. For more information, and to find a service suitable for your care, find out more about the services that we offer.

Make an enquiry

If you have any questions relating to treatment options or pricing information, get in touch with us by filling out one of our contact boxes or giving us a call on 020 3370 1041 .

Our Appointments Team have a dedicated and caring approach to finding you the earliest appointment possible with the best specialist.

If you are self-paying you don’t need a referral from your GP for a consultation. You can simply refer yourself* and book an appointment.

If you have health insurance (e.g. Bupa, Axa Health, Aviva), you will need to contact your insurer to get authorisation before any treatment, and in most cases you will also require a referral letter from your GP.

If you are not registered with a GP, we have an in-house private GP practice you can use. Alternatively, we can suggest the most appropriate course of action for you to take, given your location and individual circumstances.

*Please note – for investigations such as X-rays and MRIs, a referral will be required. However, we may be able to arrange this for you through our on-site private GP.

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