Fibroglandular Tissue: Is it Dangerous?

Patient Expert

My recent mammogram told me I have "scattered fibroglandular density."  Maybe your report used this term too.   Should you be concerned?   Probably not.

As of January 2015, twenty-one states  require radiologists to tell you if you have dense breasts. Many other states are considering similar legislation.

What makes a breast dense?

A high proportion of fibrous and glandular tissue to fatty tissue.   Every woman's breasts have milk ducts and lobules, the glandular tissue.   They also have fibrous tissue that helps connect everything.   Together these are often referred to as fibroglandular tissue.   Breasts also have fat.   Radiologists classify breast density into four groups.

Your radiologist may now be reporting to you which of the four categories of density you fit into.   From most to least dense, the terminology the radiologist uses may be:   Extremely dense, heterogeneously dense, scattered areas of fibroglandular density, or almost entirely fatty.   About 80% of women fit into the middle two categories.

Why are some lawmakers requiring you to be told about your breast density?   On a mammogram, lumps are white.   So is the fibroglandular tissue.   The fatty areas look darker.   About 10% of women have extremely dense breasts composed almost entirely of fibroglandular tissue.   These women have an increased risk of getting breast cancer.   To make the situation worse, their dense breasts make cancer harder to find because the lump that looks white on the mammogram is difficult to spot with all that white from the fibroglandular tissue.

The radiologist, fortunately, has some other tools.   Ultrasounds and MRI's can be useful in spotting a cancerous lump in a woman with dense breasts.   But they may not be covered by insurance, and they also find more suspicious areas that turn out to be benign.

The idea behind the legislation is to make sure that women know if they have the increased breast cancer risk factor of breast density.   States vary in how a woman is to be informed and what wording is used.   For someone like me who has been getting mammogram reports for years to suddenly receive a letter using an unfamiliar term like "scattered fibroglandular tissue" can be alarming.   My mammography clinic also gave me a brochure explaining the four levels of density and what it all means, so I was able to figure out that I was not at higher risk based on my breast density.

Even if you don't live in an area that requires radiologists to tell you where you fall on the density scale, the trend seems to be for radiologists to give patients this information as part of their mammogram report.   Your next mammogram letter may include some new terminology such as "fibroglandular tissue" you are not used to seeing.   Don't be alarmed.   Do talk to your doctor about your breast density level and what it means for you.

See More Helpful Articles on Density and Mammograms:

Breast Density:   Why You Should Care?

Mammograms:   Screening and Diagnostic

New Ultrasound Approved for Dense Breast Screening

Seeing Below the Surface:   My Annual Mammogram

You Should Have a Mammogram.   You Don't Need a Mammogram.   Which is It?