Occasionally, you may receive a mammogram result stating that the breasts are dense. What does this term mean and imply?
Breasts are made up of different types of tissue: fatty, fibrous, and glandular. Fibrous and glandular tissues appear as white on a mammogram and fatty tissue appears dark. If most of the tissue on a mammogram is fibrous and/or glandular, the breasts are considered to be dense.
Because cancer cells also appear as white on a mammogram, the cancer may be obscured on a mammogram in women with dense breasts.
Women found to have dense breasts on a screening study may require additional imaging depending upon their individual risk for breast cancer.
Imaging with ultrasound or MRI can pick up some cancers that may be missed on a mammogram, but these methods also have disadvantages. Because they are highly sensitive, they may give a false-positive reading, which may need additional testing or biopsy that was not necessary.