Specimen mammography-guided fine-needle aspirates of mammographically normal fatty and dense benign tissue: analysis of cell number and type.

Specimen mammography-guided 20-gauge fine-needle aspirates (FNA) were obtained from normal dense or fatty tissue. Single aspirates of dense tissue yielded greater cell counts; 74% (32 of 43) had greater than 5,000 cells as compared to 20% (19 of 93) of fatty tissue FNA, p < 0.05. Dense tissue FNA also yielded greater percentages of epithelial cells; 95% (21 of 22) had greater than 50% epithelial cells as compared to 43% (17 of 40) of fatty tissue FNA, p < 0.05. Mammographic guidance toward dense tissue is suggested for clinical studies of risk assessment using FNA of normal breast tissue.