Cancers can be hidden or “masked” by dense tissue. On a mammogram, cancer is white, but normal dense tissue also appears white. If a cancer develops in an area of normal dense tissue, it can be more difficult or sometimes impossible to see it on the mammogram, like trying to see a snowman in a blizzard. If a cancer (white) develops in an area of fat (black or dark gray), it is usually easier to detect even when it is small. Because dense tissue can hide cancers, the more fatty a breast is, the more effective the mammogram is in showing the cancer. As breast density increases, the ability to see cancer on mammography decreases.
Cancer on a mammogram in a fatty breast vs. a dense breastBrowse All Patient FAQ's