Breast Biopsy with or Without Needle Localization

Needle Localization Biopsy

A flexible, hooked wire within the localizing needle was first described by Frank and colleagues. This procedure is commonly termed needle localization biopsy, even though the needle is usually removed once the wire is in place. Ideally, the hook lodges within or adjacent to the suspicious breast lesion and prevents dislodgement from the specimen ( Figure 45-1-1 ). Under local anesthesia, the rigid introducer needle with the hooked wire within it is directed into the breast using biplanar mammographic or ultrasound guidance. The rigid needle is then removed, leaving the hooked wire in place. Because of its self-retaining feature, the wire is not easily withdrawn, advanced, or redirected. The incision should be placed directly over the mammographic abnormality, regardless of where the entry site of the wire is positioned. The direction of the dissection and dimensions of the specimen are determined by the lesion size and the relative proximity of the wire to the lesion. If the incision does not pass through the entry site of the wire, it is necessary to identify the shaft of the wire proximal to the lesion and retract it into the wound. Resection then proceeds to encompass a volume of tissue with at least 1 cm of normal-appearing tissue outside of the mammographic abnormality.

Although wire localization has gained worldwide acceptance, some technical problems remain. The surgeon may have difficulty locating the flexible localization wire, especially if the lesion is approached via an incision remote from the suspicious mass. To help reduce this problem, Homer and associates advocate the placement of a postlocalization needle. This needle, or wire stiffener, is guided percutaneously by the surgeon over the flexible hooked wire. The rigidity of the needle facilitates palpation of its course during the operative procedure. Other modifications have added distance markers along the wire and a rigid segment that makes the tip easier to palpate intraoperatively. The therapeutic adequacy of this procedure is enhanced when (1) the diagnosis is made preoperatively with fine needle aspiration biopsy (FNAB) or core biopsy and (2) the surgeon plans to resect the lesion with a border of normal-appearing breast tissue. Cox and colleagues estimate that more than 75% of patients who have diagnostic localization biopsies (palpable or nonpalpable) harbor residual breast cancer. The success and effectiveness of any invasive breast localization procedure, decrease in operating time and expense, and reduction in biopsy size are enhanced by an experienced surgeon working in close cooperation with the radiologist and pathologist. Obtaining an intraoperative specimen radiograph after wire localization is strongly recommended to corroborate complete excision. However, Hasselgren and colleagues observed a false-positive specimen x-ray film rate of 7.8% and a false-negative rate of 55%. Thus, a postoperative mammogram is also important in cases when there is discordance between the mammogram, specimen radiograph, and pathology report.

Stereotactic Core Needle Biopsy of Nonpalpable Breast Lesions

Stereotactic mammographic instruments and automated biopsy guns with core biopsy needles have radically changed the methods by which nonpalpable, mammographically detected abnormalities are managed. In many cases, stereotactic core needle biopsy (SCNB) obviates the need for open biopsy, costs less, and is associated with greater patient satisfaction. The cost benefit may be greatest for patients with BI-RADS 4 lesions rather than BI-RADS 5 lesions. The analysis by Wallace's group reiterated this view and further determined that SCNB is equivalent to needle-localized biopsy in the frequency of diagnosis of breast cancer. Furthermore, these investigators determined that there was no statistical difference between the two biopsy techniques in diagnosis for women younger than and older than 50 years of age. Even when all radiographic changes have been excised with the core biopsy technique, 10% or more patients may have additional neoplasia. Stereotactic mammographic devices use the principle of triangulation, which allows precise location of the breast lesion to be determined in three dimensions. A core of tissue, measuring approximately 2 to 2.5 mm in diameter, is obtained during the procedure.

The procedure begins by placing the patient prone on the stereotactic biopsy table with the breast dependent. The breast is compressed within the unit, and a scout film is obtained and evaluated. The skin of the breast is prepped, and the region of the skin through which the biopsy needle will pass is anesthetized with lidocaine. Using computed calculations, the center of the lesion is determined and the needle is advanced into the breast after passing through the skin puncture site ( Figure 45-1-2 ).

The core biopsy needle is advanced to the leading edge of the lesion, its position is verified, and the biopsy gun is fired. Vacuum-assisted core needle biopsy techniques allow fixation of the target area to the cutting surface of the needle resulting in even greater accuracy. After the tissue is retrieved, repeat views are obtained to document that the needle traversed or removed part or all of the lesion. The needle containing the tissue sample is then withdrawn. Additional cores can be obtained by targeting different areas within the same or other mammographic abnormalities. The cores are submitted for pathologic evaluation. After completion of the biopsy, pressure is held over the biopsy site to minimize bleeding and ecchymosis.

Core biopsy has also been found to be useful in the diagnosis of multiple synchronous neoplastic ipsilateral lesions in more than one site in the breast. Repeat biopsy of patients undergoing SCNB, with results that are not concordant with initial imaging and histopathology of the suspicious lesion, is emphasized by Dershaw's group. This practice to ensure corroboration of SCNB results is necessary for the technique to be optimally effective. Furthermore, pathologic incidence of atypical ductal hyperplasia diagnosed at SCNB requires open (needle-directed) biopsy to rule out associated ductal carcinoma in situ or invasive disease.

SCNB can also be done to evaluate suspicious microcalcifications. The extracted core of tissue should be examined with specimen mammography to confirm the presence of microcalcifications within the biopsy. For patients whose core biopsy documents the presence of carcinoma, a definitive surgical procedure should be planned. As noted previously, when the core biopsy is equivocal or shows atypia, needle-localized breast biopsy should be performed. Liberman and colleagues determined that 14-gauge SCNB achieved 99% diagnostic yield with five specimens obtained from masses. The same authors have shown that SCNB reduces the number of operations in patients with highly suspicious calcifications. Additional specimens may be essential to avoid false-negative results with the diagnosis of some calcified lesions. Discordance is minimized by removing the entire mammographic abnormality, as opposed to obtaining a portion for diagnosis. Patients who cannot lie prone or who cannot tolerate breast compression are not candidates for SCNB. In addition, if the breast compresses to less than 2 cm from the chest wall, biopsy may be inadvisable because the needle excursion is often slightly greater than 2 cm and injury to the chest wall and the pleura may occur. Complications of SCNB include hematomas, infections, possible tumor seeding of the biopsy track, and some discomfort during the procedure itself. The complication rate is acceptably low. In good hands, the procedure can be done in 30 minutes, with a false-negative rate of less than 2%. SCNBs are associated with significant savings (possibly as much as $1000 per biopsy) compared with needle-localized biopsy.

Ultrasound-Directed Core Needle Biopsy of Nonpalpable Lesions

Ultrasound guidance is now used to facilitate breast biopsies using FNAB, core needle biopsy, and open surgical excision. Ultrasound-guided FNAB offers certain advantages over SCNB. In the hands of an experienced operator, the procedure is tolerated extremely well by patients, fluid (e.g., from a small cyst) can be aspirated, and noncystic lesions can be sampled with great accuracy. Samples obtained from FNAB require evaluation by an expert cytopathologist and can be complicated by an inadequate specimen or by the inability to determine whether invasive carcinoma is present. Ultrasonography may not detect microcalcifications and is less accurate for solid masses smaller than 5 to 6 mm. The operator who performs the technique can select any site of entry on the skin. As the needle is advanced or moved, it is monitored in real time on the ultrasound monitor. Complications of ultrasound-guided fine needle aspiration include hematoma, infection, and failure to adequately sample the abnormality in question. An inadequate cytologic specimen requires additional attempts that, if unsuccessful, should be followed by core biopsy or needle-localized breast biopsy. False-negative and false-positive rates are acceptably low.

Ultrasound-guided large core needle biopsy can also be performed safely. New devices that include suction assistance and an automated firing mechanism provide a high-quality specimen using needles up to 11 gauge. Under ultrasonographic guidance, the tip of the needle is directed toward the abnormality. When the biopsy needle is appropriately positioned, the mechanism is fired, the needle is withdrawn, and the core is placed in formalin. The procedure can be repeated several times through an introducer that is first positioned adjacent to the lesion, permitting rapid reinsertion and avoiding reintroduction through breast tissue. Ultrasound-guided biopsy is particularly useful in pregnant patients and in patients with lesions that cannot be visualized mammographically. In general, a negative result of needle biopsy or of core biopsy in the face of a worrisome physical finding or a suspicious mammographic abnormality should not delay definitive surgical removal.

Direct Smear

Specimens for exfoliative cytologic analysis in the patient with suspected Paget's disease of the breast may be obtained with direct smear of the weeping eczematoid lesion of the nipple. If the areola and surrounding skin are scaly and encrusted, a sterile glass slide can be used to scrape this area gently. The direct smear technique is simple and can be performed as an office procedure. The technique is rapid and inexpensive; however, histologic confirmation is required for definitive diagnosis.

Fluid Aspiration

Fluid from palpable breast cysts is simple to aspirate with a needle and syringe ( Figure 45-1-3 ). If the cyst is not palpable, ultrasound can be used as a guide to direct the depth and location of the biopsy needle. The return of greenish brown fluid confirms the diagnosis of benign (nonproliferative) cystic disease, and, unless otherwise indicated, this fluid should not be submitted for cytologic examination. Bloody cystic fluid, on the other hand, is more likely to indicate malignancy and therefore should always be examined cytologically, either by direct smear or after centrifugation of the aspirated contents. Cystic masses should not be palpable after aspiration because the walls of the cyst collapse and conform to the surrounding breast tissue. If fluid is not obtained or the mass persists, further workup is required. If the mass resolves and later recurs, clinical and mammographic evaluations are also indicated.

Fine Needle Aspiration Biopsy

FNAB of breast masses is a safe and reliable diagnostic technique that can be performed in the office using local anesthesia. The skin overlying the palpable lesion is infiltrated with a local anesthetic. The breast lump is held relatively immobile, using one hand to gently but firmly stabilize the quadrant containing the mass. If the mass is not well defined, the procedure should be performed under ultrasound or mammographic guidance. FNAB is facilitated using an “aspiration gun” to allow the operator to apply suction while maintaining the position of the needle tip in the mass. The procedure uses a 10- to 20-mL syringe and 22- or 25-gauge needle. The needle is inserted into the mass, and suction is applied to the syringe. Moving the needle into the lesion at various angles allows clumps of cells to be dislodged from the tumor, aspirated into the syringe, and submitted for cytologic examination. Local pressure is applied after the procedure.

The diagnostic accuracy of FNAB of breast masses approximates 80%. The accuracy of this technique is strongly dependent on the skill and experience of the operator and cytologist. Close communication between these two individuals and the radiologist is required to obtain accurate results. False-positive results are unusual when the aspirated specimen is properly prepared and reviewed by a qualified cytopathologist. False-negative results are much more common, and it must be emphasized that the absence of malignant cells in the aspirate does not rule out the presence of cancer. Thus, any clinically or mammographically suspicious breast mass investigated with FNAB that does not yield a diagnosis of malignancy must be subjected to further diagnosis by means of core needle biopsy or surgical excision. This technique can also be valuable in the workup of axillary lymph nodes.