Role of ultrasound-guided fine needle cytology of axillary lymph nodes in breast carcinoma staging.

Purpose: To evaluate the efficacy of cytology on axillary lymph node ultrasound-guided aspiration biopsy in the reduction of inappropriate surgery, such as the sentinel node (SN) procedure if positive, or axillary dissection if negative.
Materials and Methods: Cytology was performed on 159 consecutive cases, on the ultrasonographically most suspicious lymph node. Lymph node histology was used as a reference standard to determine accuracy. Four different scenarios were simulated: routine axillary ultrasonography with cytology of the lymph nodes visible at ultrasonography (A), or of only the lymph nodes suspicious at ultrasonography (B), with ultrasonography limited to clinically negative axillae and cytology of the lymph nodes visible at ultrasonography (C), or only of the lymph nodes suspicious at ultrasonography only (D).
Results: Cytologic sensitivity was 58.6%, specificity 100%. Immediate axillary dissection only in the case of positive cytology would have avoided 6/6 inappropriate axillary dissections and 5/34 (14.7%) inappropriate SN, compared to routine practice (immediate dissection for palpable adenopathy, SN in the remaining cases). Each of the simulated scenarios saved inappropriate surgical procedures (A: 6 dissections, 5 SNs; B: 6 dissections, 3 SNs; C: 13 SNs; D: 11 SNs) at no expense (A and B) or limited expense (C: Euro 348, D: Euro 232 for each inappropriate surgical procedure saved).
Conclusions: Axillary lymph node cytology can save axillary dissections or sentinel node procedures and is recommended as routine practice. Routine axillary ultrasonography, with cytology of sonographically visible lymph nodes, followed by immediate axillary dissection only in case of positive cytology proved to be the best approach in terms of cost-benefit ratio.