Stereotactic core biopsy

A stereotactic core biopsy uses a 3D scanning machine (ultrasound, CT scan or MRI) to find the precise location of a tumour. A sample is removed and looked at under a microscope. This test may also be called a stereotactic needle biopsy or x-ray-guided needle biopsy. It is most often used on breast and brain tumours.

A stereotactic core biopsy is used to take a sample from a lump or an area of calcium deposits that cannot be felt but are seen on a mammogram.

A stereotactic core biopsy does not usually need any special preparation. The procedure takes about an hour but the biopsy takes only a few minutes.

• For a 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.
• The 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 or core 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.
• Tissues that are removed are sent to a lab to be looked at under a microscope.

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.

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 (incision) 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.
• Tissues that are removed are sent to a lab to be looked at under a microscope.

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.

You may have side effects after a stereotactic core biopsy of the breast, but everyone’s experience is different. Side effects of stereotactic core biopsy of the breast are usually short-term and may include:

• bruising or excessive bleeding (uncommon)
• breast tenderness
• infection at the injection site or the surgical cut site

Tell your healthcare team if you have these side effects or others you think might be from surgery. The sooner you tell them of any problems, the sooner they can suggest ways to help you deal with them.

A stereotactic core biopsy of the brain should not have any side effects. Bleeding in the brain may happen, but it is rare.

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.

Results from a stereotactic core biopsy usually provide enough information for the doctor to decide whether or not surgery is needed. Your doctor will also decide whether further tests or procedures are needed.