Management of Breast Biopsy Results ~ Algorithm 7
Breast Cancer Diagnostic Algorithms for Primary Care Providers
(Third Edition, June 2005)
Definitive
diagnosis of a breast mass can only be established
through fine needle aspiration biopsy (FNAB),
core needle biopsy, or excisional biopsy. Most
experts agree that if a mass persists for three
months, a sampling of the lesion is warranted.
Introduction to the Management of Breast Biopsy Results ~ Algorithm 7
Definitive diagnosis of a breast mass can only be established through fine needle aspiration biopsy (FNAB), core needle biopsy, or excisional biopsy. Most experts agree that if a mass persists for three months, a sampling of the lesion is warranted. Further delay in work-up is not prudent unless the diagnostic imaging evaluation shows a concordant benign lesion. Generally speaking, the best option depends on whether the mass is palpable, the availability of resources and expertise, the degree on CBE of suspected invasiveness and patient demand for a rapid diagnosis.
The pathologic findings from a biopsy must fully explain the clinical and/or the imaging findings that prompted the biopsy ("triple test"). Clinical/ radiologic/ histologic discordance occurs when the CBE and/or imaging findings are not explained by the final pathology. When repeat imaging studies or clinical exam indicate that the original radiographic or clinical finding may not have been adequately sampled ("discordant triple test result"), further biopsy is needed. Clinical/radiologic/histologic discordance carries a rate of malignancy that can be as high as 40-50% (Morris, 2003). Therefore, if the results are discordant, or if the clinician is not sure, the patient must undergo further evaluation by a breast specialist. Various options are available for obtaining concordance. These include radiology consultation, repeat image-guided biopsy, or surgical consultation. For example, a woman with a palpable mass within 2 cm of visual nipple retraction and a pathology result of normal or fibrocystic change represents discordance between the clinical findings and the pathology report (regardless of the diagnostic imaging result). The patient needs a repeat biopsy.
Core Needle Biopsy
Core needle biopsy of the breast provides a solid cylinder(s) of tissue for histologic evaluation and when properly done in appropriately selected patients is a safe, well-tolerated and cost-effective alternative to surgical biopsy. Large core needle biopsy specimens do not require subspecialty pathologist expertise for histologic diagnosis. Core biopsy may also have a 7.6% (with a range of 3.3 to 22.2% depending on the gauge of needle employed) risk of false negative diagnosis which is chiefly due to sampling error. Sampling error is reduced with the use of larger gauge needles and by obtaining multiple core biopsy samples (Shah, 2003). When core biopsy yields a result that is discordant with the clinical or imaging impression, it is incumbent on the provider to pursue the situation with repeat core biopsy or surgical biopsy. Radiologic-guided core biopsy (see below) is useful in the evaluation of the palpable breast mass that is small, deep, mobile, vaguely palpable, or multiple (Liberman, 2000). Core biopsy needle sizes may be 8, 11 or 14 gauge depending on operator preference, usually in a spring-loaded instrument, to extract several cores of tissue through a 3-5mm incision. Core biopsy is a sampling technique and is not intended to remove the lesion.
Radiologically-Guided Percutaneous Core Biopsy
A nonpalpable mass detected via imaging study can be percutaneously biopsied by a radiologist or other physician with special skills using ultrasound or mammographic (stereotactic) guidance. Stereotactic core needle biopsy is performed using special mammographic apparatus. A core biopsy needle (either an automated spring-loaded or vacuum-assisted biopsy instrument) is inserted into the lesion. Multiple tissue samples are obtained. In most centers, large core needle biopsy is replacing open surgical biopsy for the diagnosis of nonpalpable mammographic lesions.
Pre-Operative Needle (or wire) Localization Biopsy
In pre-operative needle (or wire) localization biopsy a radiologist inserts a wire through a needle into the breast to mark nonpalpable lesions detected mammographically or by ultrasound. The wire guides the surgeon to the lesion for tissue removal during an excisional biopsy; hence it is a combined radiographic and surgical technique. Today, this technique is mainly therapeutic rather than diagnostic as the majority of breast lesions have had a prior diagnosis by a radiologically guided percutaneous biopsy. For nonpalpable abnormalities the localized biopsy has less than a 2% failure rate (Bassett, 2002).
Excisional Biopsy (Lumpectomy)
Surgical removal of a breast lesion is the gold standard against which all other diagnostic techniques are compared. Excisional biopsy surgically removes the entire lesion and should include a zone of normal tissue surrounding it. The procedure requires a sterile operating room setting and leaves a small (2-4 cm) scar.
Fine Needle Aspiration Biopsy
FNA biopsy is safe, accurate and better tolerated with less bleeding and infectious complications than either large core or surgical biopsy. However, it is a highly operator-dependent procedure, requires subspecialty expertise for interpretation, and cannot distinguish invasive from non-invasive disease. Compared to other biopsy methods, FNA biopsy has a higher rate of false negative results (chiefly due to sampling error) and suspicious results (chiefly due to interpretative challenges), (Salami, 1999; Shah, 2003). When FNAB yields a result that is discordant with the clinical or imaging impression, it is incumbent on the provider to pursue the situation with a different diagnostic procedure. The use of FNA biopsy may be limited since the special expertise required to perform and interpret this form of biopsy may not be available in all areas.
Flowchart Notes
NOTE 7A : If physical findings and/or diagnostic imaging results are suspicious for a malignancy then a "negative" biopsy must be considered "discordant" and may represent a false negative result. The patient should be referred to a breast specialist for further evaluation.
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*Definitions of pathologic terms can be found in Appendix A-5: Glossary of Terms.
References
Bassett L.W. (2002, March). Options in breast biopsy. Imaging Economics.
Liberman, L., Drotman, M., Morris, E. A., LaTrenta, L. R. (2000). Imaging-histologic discordance at percutaneous breast biopsy (an indicator of missed cancer). Cancer, 89(12), 2538-2546.
Morris, A. M., Flowers, C. R., Morris, K. T., Schmidt, W. A., Pommier, R. F., Vetto, J. T. (2003). Comparing the cost-effectiveness of the triple test score to traditional methods for evaluating palpable breast masses. Medical Care, 41, 962-971.
Salami, N., Hirschowitz, S., Nieberg, R., Apple, S. (1999). Triple test approach to inadequate fine needle aspiration biopsies of palpable breast lesions. Acta Cytologica, 43(3), 339-343.
Shaw, V. I., Raju, U., Chitale, D., Deshpande, V., Gregory, N., Strand, V. (2003). False negative core needle biopsies of the breast. Cancer, 97, 1824-1831.
Updated: May, 2008.
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