Before the procedure begins, you will receive a local anesthetic injection to numb your breast.
During the procedure, you will be lying face down on a specially contoured exam table. Your breasts will hang freely through an opening in the table, and the breast being biopsied will be gently compressed between two plates. The compression is similar to but less severe than what you would experience during a mammogram.
One of the plates is marked with a grid structure that will help your doctor locate the position and depth of the lesion being biopsied. Once the lesion is located, the doctor will make a small nick in the skin and insert the biopsy needle. You will feel some pressure when the needle is inserted, but it should not be painful.
Once the needle is in place, an MRI will confirm that it is in the correct position. The exam table will move to the center of the MRI scanner, and you will hear thumping and humming sounds coming from the machine as it records images. You need to remain very still while the images are being recorded, and you may be asked to hold your breath for a few seconds at a time at various intervals.
When the placement of the needle is confirmed, tissue samples will be removed using one of the following three methods:
Fine-needle aspiration – a fine-gauge needle and syringe are used to withdraw fluid or clusters of cells.
Core-needle biopsy – a hollow needle is inserted, and three to six "cores" of tissue are removed.
Vacuum-assisted device – vacuum pressure is used to pull tissue from the breast, collecting multiple tissue samples in one pass.
You may hear clicking sounds as the samples are taken.
After the samples are taken, the needle will be removed. A small "marker" may be left in the breast so that the site of the lesion can be easily located for monitoring. It will not be visible, and you will not be able to feel it.
When the biopsy is complete, pressure will be applied to the site where the needle was inserted, and it will be covered with a dressing. No stitches will be needed.