If the presence of breast cancer is strongly suggested by physical examination, the diagnosis can be confirmed by FNAC or CNB, and the patient may be counseled regarding treatment. Treatment should not be determined based on results of physical examination and mammography alone, in the absence of biopsy results. The most reasonable approach to the diagnosis and treatment of breast cancer is outpatient biopsy (either FNAC, CNB, or EB), followed by definitive surgery at a later date if needed. This two-step approach allows patients to adjust to the diagnosis of cancer, carefully consider alternative forms of therapy, and seek a second opinion. Studies show no adverse effect from the 1to 2-week delay associated with the two-step procedure (71). Because cancer is found in the minority of patients who require biopsy for diagnosis of a breast mass, definitive treatment should not be undertaken without an unequivocal histologic diagnosis of cancer.
Fine-Needle Aspiration With FNAC, cells from a breast tumor are aspirated with a small (usually 22-gauge) needle and examined by a pathologist. Precise guidelines for this technique are available (72). It can be performed easily, with no morbidity, and is much less expensive than excisional or open biopsy. It requires the availability of a pathologist skilled in the cytologic diagnosis of breast cancer to interpret the results, and it is subject to sampling problems, particularly when lesions are deep. Cytologic diagnoses must be correlated with clinical and imaging findings to achieve triple-test concordance and to decrease the false-negative rate (73). The triple-test concordance (i.e., concordance between fine-needle aspiration, physical examination, and mammography) is the foundation of breast evaluation. The triple-test results are more powerful than each modality alone (74). The incidence of false-positive diagnoses was 0% to 0.3%, and the rate of false-negative diagnoses was 1.4% to 2.3% in several recent studies (74,75).
Core Needle Biopsy A core of tissue can be obtained from palpable lesions using a large cutting needle (76). Image-guided large-core needle biopsy is a reliable diagnostic alternative to surgical excision of suspicious nonpalpable breast lesions (77). As in the case of any needle biopsy, the main drawback is false-negative findings caused by improper positioning of the needle. False-negative findings may be reduced if core biopsy is performed with ultrasonographic guidance. The interpretation of results from CNB is classified by categories B1 to B5 (78):
B1: Normal tissue
B2: Benign lesions: fibroadenomas, fibrocystic change, sclerosing adenosis, duct ectasia, fat necrosis, abscess
B3: Uncertain malignant potential: atypical epithelial hyperplasia, lobular neoplasia, phyllodes tumor, papillary lesions, radial scar, complex sclerosing lesions
B4: Suspicious
B5: Malignant
Open Excisional Biopsy Open biopsy with local anesthesia as a separate procedure before deciding on definitive treatment is the most reliable means of diagnosis. Its utility is reserved for when the results of needle biopsy are nondiagnostic or equivocal.
Figure 21.4 Algorithm for management of breast masses in premenopausal women. (Revised and updated from Kruper L, Giuliano AE. Breast disease. In: Berek JS, Hacker NF, eds. Berek & Hacker’s Gynecologic Oncology, 5th ed. Philadelphia: Lippincott Williams & Wilkins, 2010:628, with permission.)
Figure 21.5 Algorithm for management of breast masses in postmenopausal women. (Revised and updated from Kruper L, Giuliano AE. Breast disease. In: Berek JS, Hacker NF, eds. Berek & Hacker’s Gynecologic Oncology, 5th ed. Philadelphia: Lippincott Williams & Wilkins, 2010:629, with permission.)