Significance of fine needle aspiration cytology and vacuum-assisted core needle biopsy for small breast lesions.

Background: In recent years, pathological diagnoses have been increasingly required, especially in small breast lesions, because malpractice lawsuits concerning erroneous cytological diagnoses have been commonly reported. Here, we retrospectively evaluated the significance of FNAC and VAB for small breast lesions using ultrasonography guidance.

Patients And Methods: A total of 1383 cases for which ultrasonography-guided VAB was performed between June 1996 and December 2012 were reviewed. Of these, 455 small breast lesions (239 nonpalpable and 216 nonmass lesions) were included in the study.

Results: Ultrasonography-guided FNAC was performed before VAB in 248 cases (54.5%). In 133 cases (53.6%), the results of FNAC were inconclusive. Pathological examinations using VAB revealed malignant and benign lesions in 199 and 256 cases, respectively. Of the 256 benign cases, we performed excisional biopsy in 17 cases (6.6%) and repeated VAB in 8 cases (3.1%). Excisional biopsy revealed malignant lesions in 2 cases. The reason for excisional biopsy was overdiagnosis using FNAC in 6 cases (35%). In all cases of repeated VAB, the pathological diagnosis was benign. The reason for repeated VAB was excision of the lesions in 5 cases (62.5%). The false positive and false negative rates of FNAC were 16.7% and 3.4%, respectively, whereas those of VAB were 0% and 1.0%, respectively.

Conclusion: Cytology findings for small breast lesions should be considered only when imaging and cytology indicate benign lesions. Therefore, pathological examination without cytological examination should be the initial approach.