A Core Needle Biopsy (CNB) is a common, minimally invasive procedure used by healthcare providers to obtain small samples of tissue from a suspicious area, most frequently in the breast, for laboratory analysis. This technique uses a specialized hollow needle. Because the procedure requires only a very small access point, the resultant scar is usually minimal and is often the least concerning aspect of the diagnostic process. Understanding the nature of this wound and its healing process can help manage expectations about the final cosmetic outcome.
The Core Needle Biopsy Procedure and Initial Wound
The CNB procedure is designed to be non-invasive, which is reflected in the size of the initial wound. After the area is numbed with a local anesthetic, the physician makes a tiny pre-incision, typically measuring between three and five millimeters, to allow the specialized wide-gauge needle to pass through the skin. This hollow needle is guided to the target area, often with imaging assistance, to remove several small, cylindrical samples of tissue.
Following the collection of the tissue samples, a small titanium or stainless steel clip, known as a tissue marker, is often placed at the site to permanently mark the exact location for future reference. The needle is then removed, and the small access site is typically closed without traditional stitches. Closure is usually achieved using adhesive strips, commonly called Steri-Strips, or a single dissolvable suture, which contributes significantly to the minimal scarring associated with CNBs.
Typical Scar Appearance and Healing Timeline
In the immediate aftermath of the procedure, the site will likely exhibit some bruising and mild swelling. The small incision line will initially be distinct, and the surrounding skin may turn a temporary reddish-purple color due to the underlying collection of blood, known as a hematoma. This initial discoloration and tenderness generally begin to resolve within the first one to two weeks.
Once the initial wound closes, the scar enters a remodeling phase where its appearance changes over time. For the next several months, the scar tissue typically appears pink or red and may feel slightly firm or raised to the touch. The scar will gradually begin to flatten and soften as collagen fibers reorganize beneath the skin’s surface. Final scar maturation, where the color fades to a pale, flesh-toned, or white line, can take anywhere from six months to over a year. After this period, the scar is often subtle and can be barely visible, frequently measuring less than five millimeters in length.
Strategies for Minimizing Scar Visibility
Protecting the healing tissue from sun exposure is important to minimize the final visibility of the scar. Ultraviolet rays can cause the new scar tissue to permanently darken or hyperpigment. Once the initial wound is fully closed and the adhesive strips have been removed, applying a broad-spectrum sunscreen with a high Sun Protection Factor (SPF) is necessary whenever the area is exposed to the sun.
Long-term scar management often involves the application of topical treatments to encourage a smoother, flatter outcome. Silicone sheeting or gels are widely recommended options that work by hydrating the outer layer of the skin, which helps regulate collagen production. Gentle massage of the scar tissue, once the wound is completely healed, can also be beneficial as it works to break down dense collagen bundles, helping the scar to soften and flatten over time. Avoiding any undue tension or stretching across the biopsy site, particularly in the first few weeks, will also prevent the scar from widening.
Distinguishing Normal Scar Tissue from Complications
Patients often feel a small, firm lump directly beneath the incision site, which can be a source of anxiety but is a normal part of the healing process. This firmness is commonly either a resolving hematoma (a localized collection of blood) or benign post-biopsy fibrosis, which is the body’s internal scar tissue forming at the site where the tissue was removed. Both of these are expected internal changes that soften and resolve naturally over several months.
True complications present with specific signs that warrant contacting a healthcare provider immediately. Spreading redness or increasing warmth around the biopsy site, persistent or worsening pain that is not managed with mild medication, or any discharge of pus can indicate a localized infection. Similarly, if the scar begins to grow significantly beyond the original wound boundary, becoming thick, raised, and intensely itchy, it may be developing into an abnormal scar type, such as a keloid or hypertrophic scar, which may require medical intervention.