Axillary lymph node metastasis: Fine-needle aspiration biopsy sensitivity as a function of node size, percent replacement of lymph node by tumor and tumor deposit size.

Percentage of false negative FNAs associate with investigation of metastatic disease correlates with node size, size of metastatic deposit and percentage of nodes replaced by tumor. Lymph nodes smaller than 7 mm, deposit diameter less than 6 mm and percentage replacement of less than 40% have the highest percentage of false negative results.