Core needle biopsy (CNB) as a diagnostic method for breast lesions: comparison with fine needle aspiration cytology (FNA).

In Japan, fine needle aspiration biopsy (FNA) of the breast has long been recognized as a useful diagnostic tool, and has been used in many institutions because it provides a rapid, accurate and cost-effective evaluation. However, the use of core needle biopsy (CNB) is increasing, and vacuum assisted biopsy devices have been developed to produce larger specimens for analysis. CNB is useful because the frequency of inadequate specimens is lower than in FNA, and it requires a less invasive procedure than open biopsy. CNB is also more widely used, compared to FNA, because it can provide a more definitive diagnosis of borderline lesions and can be used to distinguish between IDC and ILC. Therefore, the use of CNB with mammographic or ultrasonographic guidance is especially high for non-palpable tumors. FNA is a rapid and non-invasive procedure that is useful for mass lesions. The accuracy of FNA for non-palpable lesions is relatively low, and depends upon the skill of the aspirators, cytoscreeners and cytopathologists involved in the procedure. However, FNA for palpable masses, coupled with a physical and mammographic examination (the so-called triple test) is highly accurate for diagnosis of breast cancer when all three modalities indicate malignancy, and for a benign lesion when all three are negative.