Core biopsy

A core biopsy removes tissue from the body using a hollow needle. The tissue is then looked at under a microscope. A core biopsy is sometimes called a core needle biopsy.

The tissue removed during a core biopsy comes out as one long, narrow piece (called a core). The structure of the tissue remains intact, so doctors can see what the tissue around the cancer looks like. This gives them information that helps them decide whether to recommend further tests or treatment.

A core biopsy can be done on most areas of the body, but it is most often used to remove tissue from an abnormal area of the breast, prostate, liver, lung or lymph nodes.

There are different types of core biopsies.

A stereotactic core biopsy is a type of core biopsy used when a doctor can't feel or see the area where the biopsy needs to be done. It uses 3D imaging to guide the needle and find the exact location of the abnormal area during the biopsy. Sometimes a small piece of metal is placed in the area so that it can be easily found again later. A stereotactic core biopsy is usually used to diagnose brain and breast cancer.

This type of core biopsy uses suction from a vacuum device. It can remove multiple samples of tissue with only one needle insertion. The doctor makes a small cut (incision) in the skin and inserts the needle. They will use x-rays, an ultrasound or a CT scan to guide the needle through the cut into the area. A rotating knife inside the needle cuts the tissue and the vacuum pulls it inside the needle.

A vacuum-assisted core biopsy is most often used to diagnose breast cancer.

Your doctor may do a core biopsy if they find a lump or abnormal area during a physical exam or on an imaging test, such as an x-ray or ultrasound. Sometimes doctors need to do a core biopsy after a fine needle aspiration to confirm a diagnosis.

A core biopsy is used to:

• diagnose or rule out cancer
• find out the type of tumour
• find out the grade of cancer

A core biopsy is done in a doctor's office, clinic or hospital as an outpatient procedure (you won't need to stay overnight). You usually don't need to take any steps to prepare for it, but your healthcare team will tell you if you do. The entire procedure takes about 15 to 30 minutes. The part that involves using the needle and removing the tissue is very quick and takes about a minute.

During the test, you will sit or lie down. After numbing the area with a local anesthetic, the doctor will take several samples of tissue from it using a hollow needle. The tissue is sent to a lab to check for abnormal cells.

If the doctor can feel the lump, they can use a physical exam to help guide the needle. If they can’t feel the lump, the doctor will use imaging tests such as an ultrasound, CT scan or an x-ray to help guide the needle.

Depending on where you had the core biopsy, you may need to avoid heavy physical activity for 1 or 2 days after the procedure.

A stereotactic biopsy of the breast is done if a mammography shows that there is an abnormal area in the breast.

• For a stereotactic biopsy of the breast, you lie on your stomach on the biopsy table. The breast to be biopsied hangs through an opening in the table. The table is raised and the doctor performs the biopsy from below. Sometimes the procedure can be done in a sitting position.

• Your breast is compressed and held in place between 2 plates on the mammography machine. The radiologist looks at the images and finds the site to be sampled.

• A local anesthetic is given to numb the area and a small cut (incision) is made in the skin.

• The biopsy is done using a hollow needle, a vacuum-powered device or both. A special machine guides the needle or a probe to the abnormal area and samples of tissue are taken.

• A small metal clip may be left in the site of the biopsy as a marker so the area can be found again easily if more surgery is needed.

After the biopsy is done, the needle is removed and ice and pressure may be applied to the area. A small bandage is used to cover the biopsy site. You won’t need stitches.

The tissue removed is sent to the lab to be examined.

A stereotactic core biopsy may be used for tumours that likely can’t be removed with surgery, such as tumours that are deep in the brain.

• A local anesthetic is used to freeze the scalp. You may be given a general anesthetic.

• A special frame is fastened to the head to hold it in place while the surgeon targets the tumour. The surgeon makes a cut in the scalp and drills a small hole in the skull.

• An MRI or a CT scan is usually used to help the surgeon guide a hollow needle into the tumour and remove tissue samples for biopsy.

After the biopsy is done, the needle is removed and the incision is closed with stitches. A small bandage is used to cover the biopsy site. The stitches can be removed in 10 to 14 days.

The tissue removed is sent to the lab to be examined.

Side effects of a core biopsy will depend mainly on the type of biopsy and where it is done. Tell your healthcare team if you have side effects that you think are from the core biopsy. The sooner you tell them of any problems, the sooner they can suggest ways to help you deal with them. In general, side effects may include:

• bleeding or bruising
• tenderness
• swelling
• pain
• infection (red, warm or painful skin following the procedure)
• scarring

Biopsy samples are sent to a pathology lab. A pathologist (a doctor who specializes in the causes and nature of disease) looks at the cells to see if they contain cancer. The pathology report shows the type of cells present, their characteristics and whether they are normal, cancerous or abnormal but non-cancerous.

If the report shows that the cells are cancerous, they may need to be studied further. You may need further tests to find out the type of tumour, how fast the cells are growing and if cancer cells have spread to the surrounding normal tissue.

Find out more about cell and tissue studies.

Preparing children before a test or procedure by explaining what will happen during a test, such as what the child will see, feel and hear, can be very helpful. Preparing children before a test or procedure can help lower their anxiety, make them more cooperative and develop their coping skills.

Preparing a child for a core biopsy depends on the age and experience of the child. Find out more about helping your child cope with tests and treatments.