Ultrasonographically and stereotactically guided fine-needle aspiration cytology of non-palpable breast lesions: cyto-histological correlation

Objective:  To determine the diagnostic accuracy of ultrasonographically (US) and stereotactically guided fine needle aspiration cytology (FNAC) for the diagnosis of non-palpable breast lesions.
Patients and methods:  From January 2002 to December 2004, 470 women with 478 mammographically detected non-palpable breast lesions had US or stereotactically guided FNAC of the breast lesion. Subsequent histological evaluation of the same lesion was performed at the Institute of Oncology Ljubljana, Slovenia. The correlation between the original cytological and histological diagnosis was assessed and the sensitivity, specificity, positive predictive value and negative predictive value were calculated.
Results:  Among US-guided FNACs, 144 (53.5%) were histologically verified benign lesions and 125 (46.5%) were carcinomas. Cytological diagnoses were: true positive (TP) in 63 cases (50.4%), suspicious in 35 (28%), false negative (FN) in eight (6.4%), and in 19 (15.2%) cases, the material was inadequate for diagnosis. In the stereotactically guided FNAC group, there were 209 women with 209 lesions, with 95 (45%) histologically proven carcinomas and 114 (55%) benign lesions. Cytological diagnoses were TP in 49 (51.6%) cases, true suspicious in 21 (22.1%), FN in nine (9.5%), and in 16 (16.8%) cases, the material was not adequate for the diagnosis.
Conclusion:  The sensitivity of 88.7% and specificity of 98.6% for US-guided FNAC and 84.5% and 100% for stereotactically guided FNAC, respectively, suggest that clinicians can rely upon cytological diagnosis for planning further management of women with non-palpable breast lesions.