Accuracy of fine-needle aspiration cytology of axillary lymph nodes in breast cancer patients - A study of 115 cases with cytologic-histologic correlation

BACKGROUND. Fine-needle aspiration (FNA) cytology of axillary lymph nodes is a simple, minimally invasive technique that can be used to improve preoperative determination of the status of the axillary lymph nodes in patients with breast cancer, thereby serving as a tool with which to triage patients for sentinel versus full lymph node dissection procedures. The aim of the current study was to determine the sensitivity and specificity of FNA cytology to detect metastatic breast carcinoma in axillary lymph nodes. METHODS. A total of 115 FNAs of axillary lymph nodes of breast cancer patients with histologic follow-up (subsequent sentinel or full lymph node dissection) were included in the current study. The specificity and sensitivity, as well as the positive and negative predictive values, were calculated. RESULTS. The positive and negative predictive values of FNA cytology of axillary lymph nodes for metastatic breast carcinoma were 1.00 and 0.60, respectively. The overall sensitivity of axillary lymph node FNA in all the cases studied was 65% and the specificity was 100%. The sensitivity of FNA was lower in the sentinel lymph node group than in the full lymph node dissection group (16% vs 88%, respectively), which was believed to be attributable to the small size of the metastatic foci in the sentinel lymph node group (median, 0.25 cm). All false-negative FNAs, with the exception of I case, were believed to be the result of sampling error. There was no 'true' false-positive FNA case in the current study. CONCLUSIONS. FNA of axillary lymph nodes is a sensitive and very specific method with which to detect metastasis in breast cancer patients. Because of its excellent positive predictive value, full axillary lymph node dissection can be planned safely instead of a sentinel lymph node dissection when a preoperative positive FNA result is rendered.