Axillary lymph node status in breast cancer staging: What patient and tumor factors affect the accuracy of ultrasound-guided fine needle aspiration?

1126 Background: The purpose of the study is to evaluate the accuracy of ultrasound-guided fine needle aspiration (FNA) of axillary lymph nodes(ALNs) in patients with breast cancer and to determine factors that influence accuracy of ultrasound-guided FNA. Methods: Retrospective review of patients with breast cancer who had FNA of ALNs as well as sentinel lymph node excision or complete axillary dissection. Patients treated with neoadjuvant chemotherapy were excluded. 55 axillary FNAs in 54 patients were included in the final analysis. Pathology reports were reviewed for size of the primary tumor, FNA results, number of positive ALNs, and greatest tumor size in ALNs. FNA was performed if a suspicious lymph node was identified. Surgical sentinel lymph node biopsy or full axillary dissection were the reference standard. Micrometastases (< 0.2 mm) and isolated tumor cells in the lymph node were included in the negative group. Atypical and nondiagnostic FNA results were considered negative cytologic results. S...