A core biopsy is a minimally invasive medical procedure used to obtain small cylinders of tissue from a suspicious area in the body, often following an abnormal result from an imaging test such as a mammogram, ultrasound, or MRI. This technique uses a specialized hollow needle to extract tissue for laboratory analysis. The procedure provides a definitive diagnosis without the need for traditional surgery. It is performed as an outpatient procedure using local anesthesia, meaning the patient is awake but the biopsy site is numb.
Why Core Biopsy is Necessary
The primary reason a core biopsy is performed is to establish a clear diagnosis when imaging studies reveal a concerning area, such as a suspicious lump or microcalcifications. It is preferred over methods like fine-needle aspiration (FNA) because it removes a larger, more intact piece of solid tissue. While FNA collects individual cells or fluid, the core biopsy provides a solid tissue sample.
This larger sample size is necessary for detailed pathology analysis, which involves a histological study of the tissue structure. Pathologists require this preserved structural arrangement, often called “tissue architecture,” to accurately determine if a lesion is benign or malignant. Analyzing the architecture allows for precise grading of a tumor, differentiation between cancer types, and identification of specific characteristics, such as hormone receptor status. This information is essential for guiding subsequent treatment planning.
Performing the Core Biopsy Procedure
The core biopsy procedure begins with the patient being positioned appropriately, depending on the location of the abnormality. The skin around the biopsy site is thoroughly cleaned, and a local anesthetic is injected to numb the area. Patients typically feel a brief sting from the injection, followed by a sensation of pressure but not pain during the rest of the procedure.
A small nick is often made in the skin to allow the specialized biopsy needle to pass through easily. Imaging guidance is central to the process, with the physician using ultrasound, stereotactic mammography, or MRI to visualize the exact target in real-time. This ensures the needle is precisely directed to the abnormal tissue, maximizing the chance of a diagnostic sample.
The biopsy device is inserted, and the needle, which may be spring-loaded or vacuum-assisted, quickly collects several small core samples of tissue. A clicking or snapping sound is often heard when the device is fired, which is a normal part of the process. Typically, multiple cores are taken from the suspicious area to ensure adequate tissue for testing.
After the tissue samples are secured, a tiny metal clip, or marker, is often placed at the biopsy site. This clip marks the exact location of the abnormality on future imaging tests, which is useful if further treatment or follow-up is needed. The biopsy needle is then removed, and pressure is applied to the site to minimize bleeding and bruising.
Post-Procedure Care and Receiving Results
Immediate care involves applying firm pressure to the site for several minutes to achieve hemostasis, followed by placing a sterile dressing or bandage. Patients are usually advised to wear a supportive garment, such as a sports bra for breast biopsies, for the first 24 to 48 hours to reduce swelling and discomfort. Mild soreness and bruising at the biopsy site are common and should gradually resolve over about a week.
Patients are restricted from strenuous activity or heavy lifting for 24 to 48 hours following the biopsy. Over-the-counter pain relievers, such as acetaminophen, are usually recommended for discomfort. Patients should confirm with their doctor about avoiding blood-thinning medications. Patients should contact their healthcare provider if they experience heavy bleeding, signs of infection like increased warmth or redness, or severe pain.
The collected tissue samples are immediately sent to a pathology laboratory for analysis. A pathologist examines the tissue under a microscope, performing specialized tests to determine the precise diagnosis. Results are typically available within a few days to a week, though complex cases may take up to 10 to 14 days. The final step involves a follow-up appointment with the referring physician to discuss the pathology report and determine the next steps in care.