A breast biopsy clip, also referred to as a tissue marker, is a miniature device placed inside the breast immediately following a needle biopsy procedure. It serves as a permanent, visible landmark on future medical images, such as mammograms or ultrasounds, showing the precise location from which a tissue sample was removed. Placing this device ensures that healthcare providers can accurately find the exact site of the original finding for future monitoring or treatment.
The Clinical Necessity of Biopsy Site Markers
The necessity for using a biopsy clip arises from the nature of breast tissue and the minimally invasive technique of a needle biopsy. After a small tissue core is removed, the microscopic cavity tends to collapse and heal, often leaving no discernible trace on subsequent imaging within a few weeks or months. Without a marker, the original site of concern, which may have been only a few millimeters in size, would become virtually impossible to locate again with precision.
The clip provides an unambiguous, enduring reference point for follow-up care. If the biopsy result is benign, or non-cancerous, the marker identifies the area already investigated. This prevents the need for repeat biopsies on the same finding during routine surveillance, reducing unnecessary procedures.
The marker is also invaluable if the biopsy reveals a malignant, or cancerous, finding. The clip becomes the target for pre-surgical planning, ensuring the surgeon can accurately localize and remove the precise area of the breast tissue. This process, known as localization, is necessary for a successful lumpectomy or surgical excision.
The clip is also useful if the patient undergoes neoadjuvant therapy, which is chemotherapy administered before surgery. This treatment shrinks the tumor, and in some instances, the tumor may shrink so significantly that it is no longer visible on imaging. The biopsy clip remains to mark the original tumor site, guiding the surgeon to the area that still requires removal.
Materials and Placement During the Procedure
Breast biopsy clips are extremely small, typically measuring less than three to four millimeters—roughly the size of a sesame seed or a grain of rice. They are constructed from surgical-grade, biocompatible materials safe for long-term implantation. Common materials include titanium or stainless steel, which are also used in other medical devices like hip replacements.
Manufacturers may also use materials such as ceramic, nitinol, or polymer compounds, sometimes coated with a hydrogel. The composition ensures the clip is visible on all common imaging modalities, including mammography, ultrasound, and magnetic resonance imaging (MRI). The clip is inserted immediately after the tissue samples are taken, while the biopsy needle is still positioned at the site of the original finding.
Placement is a quick, final step of the biopsy procedure, guided by the same imaging technique used for the biopsy, such as stereotactic mammography or ultrasound. This guidance confirms the clip is accurately deployed at the center of the tissue removal site. Since the breast is already numbed with a local anesthetic, placing the clip usually causes no additional discomfort.
Living with the Marker: Permanence and Safety
The breast biopsy clip is intended to be a permanent fixture, designed to remain safely within the breast tissue indefinitely. These markers are made from inert materials that do not degrade or react with the body’s tissues, and they are generally not felt by the patient due to their small size and deep placement. The clip is only routinely removed if the patient requires surgery to excise the surrounding tissue, in which case the marker is taken out along with the biopsied area.
A common concern is the safety of the marker during future medical procedures, particularly MRI scans. Modern biopsy clips are almost universally made from non-ferromagnetic materials, such as pure titanium or specific alloys, which are safe for use in magnetic resonance environments. Patients should inform the MRI technologist that a breast marker is present, as it may create a small, localized distortion in the image, known as an artifact.
The markers are too small to be detected by standard security checkpoints and will not trigger airport metal detectors. Non-metallic markers are available for the rare instance a patient has a known metal sensitivity, though the risk of an allergic reaction to titanium is low. While the clip is anchored to prevent migration, it may shift slightly from its initial placement, but it cannot travel to other parts of the body.