If a suspicious lump or abnormality is found when a woman is breast-feeding, diagnostic mammography and/or other breast imaging exams will be performed. Mammography in a lactating woman is considered safe and can be accurate if performed properly.
Most healthcare professionals suggest that the breast should be completely emptied of milk immediately before the mammogram, either via nursing or a breast pump. Emptying the breast of milk decreases the density through which the x-rays must penetrate and helps improve image quality.
Because lactating breasts tend to be denser, mammogramy is not as effective. Although 10% to 15% of masses can be missed with a mammogram in a non-lactating breast, this percentage can be as high as 25% in lactating breasts. For this reason, biopsy is often necessary to determine whether the abnormality is cancerous or benign.
Fine needle aspiration (FNA) involves using a thin needle to sample fluid or cells from the breast. FNA often is used to identify or drain cysts (collections of fluid). Core needle biopsy or open surgical biopsy also can be performed safely, but is usually reserved for cases in which FNA cannot be used to make a diagnosis.
The vast majority of breast abnormalities discovered during lactation are inflammatory or infectious complications, not breast cancer. Nasopharyngeal organisms (such as a cold virus) from the infantís mouth, sinuses, and other air passages can be a common source of infection in breast-feeding women.