context: If your doctor finds something questionable during a routine breast exam, mammogram, or ultrasound, they may recommend this test. During a breast biopsy, your doctor removes cells or a small piece of tissue from that part of your breast. They examine it under a microscope to look for signs of cancer. It's the only way to know for sure if a potential trouble spot is cancer. There are different breast biopsy procedures. The method your doctor recommends will depend on: The size of the breast lump or suspicious area Where it's located If there's more than one abnormal area If you have other medical problems Your personal preferences Fine-needle aspiration. A small needle is used to take a sample of cells from the area in question. If the lump is a cyst (a fluid-filled sac), the procedure may cause it to collapse. This fluid will be looked at under a microscope for any signs of cancer. If the lump is solid, cells can be smeared onto slides for examination. Ultrasound-guided core biopsy. A needle is placed into the breast tissue. Ultrasound helps confirm the exact location of the potential trouble spot so the needle is placed correctly. Tissue samples are then taken through the needle. Ultrasound can see the difference between cysts and solid lesions. Stereotactic biopsy. You'll be helped into a position that centers the area to be tested in the window of a specially designed instrument. Mammogram films called SCOUT films are taken so the radiologist can examine the area to be biopsied. Using a local anesthetic, the radiologist makes a small opening in the skin. A needle is placed into the breast tissue, and computerized pictures help confirm the exact placement. Tissue samples are taken through the needle. It's common for the medical professionals to take multiple tissue samples (about three to five). Open excisional biopsy. This is surgery to remove an entire lump. The tissue is then studied under a microscope. If a section of normal breast tissue is taken all the way around a lump (called a lumpectomy), the biopsy is also considered a breast cancer treatment. In this technique, a wire is put through a needle into the area to be biopsied. An X-ray helps make sure it's in the right place, and a small hook at the end of the wire keeps it in position. The surgeon uses this wire as a guide to locate the suspicious tissue. Sentinel node biopsy. This method helps ensure that only the lymph nodes most likely to have cancer are removed. It pinpoints the first lymph node a tumor drains into (called the sentinel node). To locate it, a radioactive tracer, a blue dye, or both, are injected into the area around the tumor. The tracer travels the same path that the cancer cells would take, making it possible for the surgeon to determine the one or two nodes most likely to have cancer. Cells or tissues that are removed using any of the methods described above are given to a pathologist, a doctor who specializes in diagnosing suspicious tissue changes. You may need to wear a special bra and dressings over the breast biopsy site for a few days after the procedure. Small strips of tape, or possibly stitches, will remain over the incision site. Don't try to remove these yourself. They'll either be removed at a follow-up appointment or will fall off by themselves. You may be asked to apply medicine or ice to the biopsy area or change the bandages at home. Your doctor will give you advice on showering, bathing, and wound care. You'll get a prescription for pain relief if you need it, but you might be OK with an over-the-counter pain reliever. To lower the risk of bleeding, don't take aspirin or products containing aspirin for the first 3 days after the procedure, unless a doctor tells you to. The area of the biopsy might be black and blue for a few days afterward, too.