https://my.clevelandclinic.org/health/diagnostics/24204-breast-biopsy-overview

Core Perspective

Starting from clinical application and decision-making path, this article elaborates on how stereotactic core biopsy becomes the gold standard for evaluating breast lesions of BI-RADS category 4 and above that are not palpable, and provides a detailed explanation of how the specifications of the needle (length, diameter/size) affect the success rate of sample collection.

With the increasing popularity of breast imaging examinations, a large number of tiny and non-encapsulated lesions that could only be detected on mammography or ultrasound have been identified. These lesions may be benign or could be early signs of cancer. How can a reliable pathological diagnosis be obtained without undergoing a traumatic open surgery? The answer is breast stereotactic biopsy, which has become the "gold standard" for addressing such issues.

When a patient's mammogram shows microcalcifications or structural distortions of BI-RADS 4A or above, the clinical pathway usually leads to stereotactic biopsy. Its advantages are as follows:

• First, accuracy. It can sample the abnormal area within millimeter range, with the error controlled within 1-2 millimeters.
• Second, minimally invasive. Only a 3-4 millimeter skin incision is needed to complete it, and no obvious scar will remain after the operation.
• Third, efficiency. One puncture can obtain multiple tissues, which is sufficient to meet the needs of routine pathology and immunohistochemical testing.

In actual practice, the choice of the needle type directly determines the success or failure of the biopsy. The "length" and "diameter (specification)" are the key variables. For example, for patients with thicker breasts or lesions located at the back, a longer puncture needle (such as 10cm or 15cm) needs to be selected to ensure reaching the target depth. The diameter of the needle (usually denoted as G, with a larger G number indicating a thinner tube diameter) affects the sample volume and tissue integrity. For cases that require obtaining sufficient tissue for hormone receptor testing, a thick needle of 12G or 14G is often used; for minor calcifications that only need to rule out the risk of malignancy, a fine needle of 16G or 18G combined with vacuum assistance can also achieve satisfactory results.

Another key application of stereotactic biopsy is "marker clip placement." After the sampling is completed, a titanium marker clip is released into the lesion area through the same biopsy needle. This provides a precise target for potential subsequent surgical resection or radiotherapy; even if the lesion has been completely removed, it can accurately locate the original site.

Therefore, stereotactic core biopsy is not only a diagnostic tool but also an integral part of the treatment plan. It offers patients a "one-step solution" for diagnosis, eliminating the possibility of a second surgery. It can be said that without the development of stereotactic biopsy technology, there would be no widespread implementation of modern breast-conserving surgery and precise radiotherapy.