Ultrasound‐guided fine‐needle aspiration of axillary lymph nodes in breast cancer: Diagnostic accuracy and role in surgical management

BACKGROUND: The objective of this study was to evaluate the accuracy of fine needle aspiration cytology (FNAC) of axillary lymph nodes (LN) in breast cancer, to compare the results of FNAC and pathological examination, and to distinguish patients with 1 to 2 metastatic LNs from those with ≥3 metastatic LNs in patients with FNAC-positive patients. PATIENTS AND METHODS: This study included 198 breasts of 196 patients with breast cancer who underwent FNAC and surgery for the primary and axilla without neoadjuvant chemotherapy from January 2010 to August 2016. Axillary nodal status was assessed by ultrasound (US), and whether FNAC-positive had three or more suspicious LNs on US imaging was examined. RESULTS: The results of FNAC were positive in 75 (38%), negative in 97 (49%), suspicious in 2 (1%), indeterminate in 5 (2.5%), and insufficient in 19 patients (9.5%). FNAC sensitivity, specificity, positive predictive value, and negative predictive value were 62.6%, 100%, 100%, and 62.0%, respectively. Whereas 53% (18/34) of patients with false-negative FNAC had one metastatic LN on final pathology, 61% (47/77) patients who were FNAC-positive had three or more metastatic LNs. In the FNAC-positive patients, all patients had ≥3 metastatic LNs if they had ≥3 suspicious LNs on US imaging. CONCLUSION: Patients with positive cytology were more likely to have ≥3 positive LNs compared to false-negative cytology patients. Patients with ≥3 abnormal LNs on US and positive FNAC might require axillary dissection.