Minimal risk of macrometastases in the non-sentinel axillary lymph nodes in breast cancer patients with micrometastatic sentinel lymph nodes and preoperatively ultrasonically uninvolved axillary lymph nodes

Micrometastases in the sentinel lymph node (SLN) carry a considerable risk of macrometastases in the non-sentinel lymph nodes (NSLN), resulting in axillary lymph node dissection (ALND). Preoperative ultrasound (US) examination of the axillary lymph nodes combined with a fine-needle aspiration biopsy (FNAB) has been proved to discover metastases in the axillary lymph nodes. The aim of our study was to assess the risk of macrometastases in NSLN in patients with micrometastatic SLN after a preoperative US examination of the axillary lymph nodes. The study included 36 patients in whom, after preoperative axillary US, micrometastases in the SLN were revealed and ALND was subsequently performed. At final histopathology, no macrometastases were discovered in the NSLN. In four patients, additional micrometastases were discovered in the NSLN. In conclusion, the risk of macrometastases in the NSLN in patients with preoperatively ultrasonically uninvolved axillary lymph nodes is minimal.