Preoperative fine needle aspiration of axillary lymph nodes in breast cancer: clinical utility, diagnostic accuracy and potential pitfalls.

OBJECTIVE

This study evaluates the diagnostic accuracy of axillary lymph node fine needle aspiration (FNA) cytology in breast cancer and correlates it with clinical parameters/outcomes.

STUDY DESIGN

A total of 91 females underwent FNA of axillary lymph nodes at our institution from January 2007 to February 2013. The cases were classified as 'positive', 'negative for malignancy' and 'nondiagnostic'.

RESULTS

Forty-six cases (50.5%) had a histologic follow-up (4.4 ± 3.1 months); of these, 22 (47.8%) were true positive, 7 (15.2%) were true negative, 2 (4.3%) were false negative, 5 (11%) were false positive and 10 (21.7%) were nondiagnostic. However, cytological review of all false positive and false negative cases confirmed the presence or absence of tumor, respectively. All false positive cases had undergone preoperative neoadjuvant chemotherapy, with no residual tumor present, and a treatment effect identified only histologically. Meanwhile, the 2 false negative cases involved micrometastasis (≤ 1.5 mm). Thus, if we exclude these false positive cases (complete responders), then the sensitivity, specificity, positive predictive value and negative predictive value were 91.7, 100, 100 and 77.8%, respectively. All preoperative FNA-positive axillary lymph nodes were spared from sentinel lymph node biopsy except for 3 of 27 (11.1%).

CONCLUSION

We suggest that axillary lymph node FNA is a highly sensitive technique with a low false negative rate (4.3%) and a diagnostic accuracy of 93.5%.