What is the significance of extensive fibroglandular (dense breast) tissue in both breasts?

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Last updated: May 20, 2025View editorial policy

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From the Guidelines

Extreme fibroglandular tissue in both breasts refers to very dense breast tissue composed of a high proportion of fibrous connective tissue and glandular tissue (milk-producing glands) relative to fatty tissue, which appears white on mammograms and makes it more difficult for radiologists to detect potential abnormalities. Women with extremely dense breasts have a higher risk of developing breast cancer, with a relative risk of 2.1 compared to those with average breast density 1. This increased risk is due to the dense breast tissue itself, as well as the decreased sensitivity of mammography in detecting abnormalities in dense breasts 1.

Some key points to consider:

  • Breast density is determined by genetics, hormonal factors, and body weight, with younger women and those with lower BMI typically having denser breast tissue 1.
  • Density often decreases with age and menopause but varies significantly between individuals 1.
  • Women with extremely dense breasts may benefit from additional screening methods beyond standard mammography, such as ultrasound, MRI, or 3D mammography (tomosynthesis) to improve cancer detection 1.
  • Understanding breast density is important for personalized breast cancer screening strategies, and women with extremely dense breasts should discuss supplemental screening options with their healthcare provider 1.

It's essential to note that the relative risk of breast cancer associated with dense tissue is about 1.2 for heterogeneously dense and 2.1 for extremely dense breasts compared to average breast density 1. Therefore, women with extremely dense breasts should prioritize supplemental screening methods and discuss their individual risk factors with their healthcare provider to determine the best screening strategy.

From the Research

Definition of Extreme Fibroglandular Tissue

  • Extreme fibroglandular tissue refers to a high percentage of dense tissue in the breast, which can make it more difficult to detect breast cancer through mammography 2.
  • Fibroglandular tissue is composed of glandular and fibrous tissues, and a high amount of this tissue can increase the risk of breast cancer 3.

Detection of Breast Cancer in Women with Extreme Fibroglandular Tissue

  • Mammography is the mainstay of screening for breast cancer, but it has limitations, especially in women with dense breast tissue 4.
  • Other imaging modalities, such as ultrasound and magnetic resonance imaging (MRI), can be used as adjunctive screening tools, especially for women at high risk for breast cancer 2, 5, 3.
  • MRI has been shown to be more sensitive than mammography and ultrasound in detecting breast cancer, especially in women with dense breast tissue 2, 3.

Screening Recommendations for Women with Extreme Fibroglandular Tissue

  • The Society of Breast Imaging and the American College of Radiology recommend that women with dense breast tissue consider additional screening modalities, such as ultrasound or MRI 4.
  • Women with a high risk of breast cancer, including those with a family history or genetic mutations, may benefit from more frequent screening and the use of additional imaging modalities 5, 3.
  • Breast self-examination and clinical breast examination can also be used as screening tools, especially in populations with limited access to mammography and other imaging modalities 6.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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