Critical clinicopathologic analysis of 23 cases of fine-needle breast sampling initially recorded as false-positive - The 44-year experience of the Institut Curie

BACKGROUND. Because false-positive cytologic diagnoses in breast tumors are rare, few cases have been reported, although their consequences may be hig hly detrimental to the patient. The authors report the Institut Curie's exp erience, by using a multidisciplinary approach. METHODS. Of 9334 benign breast tumors examined preoperatively for cytologic diagnosis by fine-needle sampling (FNS), the 23 (0.25%) FNS cases consider ed to be false-positive were retrospectively reviewed and analyzed. RESULTS. Tumors were situated close to the nipple in 7 cases and away from the nipple in 16 cases. Tumor stage was T0 for 1 case, T1 for 18 cases, and T2 for 4 cases. Radiologically, six tumors were classified as malignant, s even as indeterminate or suspicious, and nine as benign. Three of six tumor s studied by flow cytometry were DNA aneuploid. Based on a multidisciplinar y clinicopathologic review, 20 FNS cases were finally classified as false-p ositive, and the remaining 3 tumors with malignant FNS and subsequent benig n histology were classified as true-positive, because local and/or metastat ic progression was observed in the short term. CONCLUSIONS. The authors' review suggests two categories of false-positive cases: the first in which cytologic benign patterns are overdiagnosed, and the second in which atypical morphologic criteria were present. Nevertheles s, as shown by the malignant course in three cases, patients with malignant preoperative FNS and corresponding benign histology always require close c linical follow-up. Finally, surgical overtreatment rate could be decreased if all radiologically benign tumors with positive/suspicious FNS were subje ct to intraoperative frozen section examination. Cancer (Cancer Cytopathol) 2001;93:132-139, (C) 2001 American Cancer Society.