BACKGROUND. Several arguments are used for choosing either fine-needle aspi
ration cytology (FNAC) or core needle biopsy (CNB) in the evaluation of bre
ast lesions. Comparison of published data on both methods is complicated by
differences in study design, calculations, and operator experience. The ob
jective of this study was to make a direct comparison of both methods.
METHODS. In 286 breast lesions (cysts and microcalcifications without a sof
t tissue mass excluded), both ultrasound-guided FNAC and CNB were performed
in the same session by the same operator. Histologic follow-up was collect
ed, and for those lesions that were not excised the results of the most rec
ent mammography was used. A combination of the findings of both FNAC and CN
B were evaluated.
RESULTS. Core needle biopsy and FNAC do equally well for sensitivity (88% v
s. 92%), positive predictive value for malignancy (99% vs. 100%), and inade
quate rate (7% vs. 7%). However, statistical differences are found for the
specificity (CNB, 90%; FNAC, 82%). In addition, differences are found in th
e positive predictive value of both suspicious (CNB, 100%; FNAC, 78%) and a
typia (CNB, 80%; FNAC, 18%) and for the suspicious rare (CNB, 5%; FNAC, 13%
) reflecting difficulties in interpreting some FNACs. Combining the finding
s of both FNAC and CNB results in an increase in absolute sensitivity, a de
crease in the positive predictive value of atypia compared with FNAC and CN
B per se, and a decrease in the inadequate rate for cancers.
CONCLUSIONS. For the lesions selected in this study, FNAC and CNB are compa
rable for most parameters, but CNB has a higher specificity and lower suspi
cious rate. Combining results of FNAC and CNB leads to an increase in absol
ute sensitivity without affecting specificity and a decrease in the inadequ
ate rate for cancers. Cancer (Cancer Cytopathol) 2001;93:146-150, (C) 2001
American Cancer Society.