The value of preoperative ultrasound guided fine-needle aspiration cytology of radiologically suspicious axillary lymph nodes in breast cancer

BACKGROUND: Preoperative ultrasound (US) and eventually US-guided fine-needle aspiration cytology (FNAC) of suspicious axillary lymph nodes (ALN) is a standard procedure in the work-up of suspicious breast lesions. Preoperative US FNAC may prevent sentinel node biopsy (SNB) procedure in 24-30% of patients with early stage breast carcinoma. The aim of this study was to evaluate the institutional results of this preoperative diagnostic procedure. MATERIALS AND METHODS: A total of 182 cases of preoperative FNAC of suspicious ALN where retrieved from the pathology files. The results were compared with the final histology and staging. False negative (FN) FNAC cases were reviewed and possibly missed metastatic cases (2) were immunostained with the epithelial marker AE1/AE3. RESULTS: There were no false positives, whereas 16 cases were FN. In all but one case the FN's represented sampling error. Half of the 16 FN cases in this series were macrometastases. DISCUSSION: About 83% of the preoperatively aspirated cases were N+, indicating that a radiologically suspicious ALN has a very high risk of being metastatic. Preoperative US guided FNAC from radiologically suspicious ALN is highly efficient in detecting metastases. Depending on national guidelines, a preoperative, positive ALN FNAC might help to stratify the patients as to SNB and/or ALN dissection.