Purpose: To evaluate the contribution of guided fine-needle aspiration cytology in reducing unnecessary biopsies of benign solid nonpalpable breast lesions with low suspicion of malignancy at mammography.
Material and methods: An evaluation was made of a consecutive series of 2444 solid nonpalpable breast lesions detected by mammography and undergoing guided (sonography or stereotaxy) fine-needle aspiration cytology. Surgical biopsy was made in the presence of strong suspicion of malignancy at mammography and/or of abnormal cytology.
Results: The sensitivity was 96.7% and the specificity 77.7% (average follow-up 2.77 years). False-negative/inadequate cytology associated with low suspicion of malignancy at mammography resulted in a diagnostic delay in 27 cancer cases (invasive 20, intraductal 7). On the other hand, cytology led to surgical biopsy in 53 cancer cases which might not otherwise have been biopsied because of low radiological suspicion of cancer. Surgical biopsy of all cases, to avoid diagnostic delays, would have increased the benign biopsy rate by a factor of 4.5, with a rise in the benign: malignant biopsy ratio from 0.44:1 to 1.93:1.
Conclusion: Stereotaxy- or ultrasound-guided fine-needle aspiration cytology of nonpalpable mammographic abnormalities can achieve a sharp reduction in unnecessary benign biopsies in cases of low suspicion of malignancy at mammography.