From the Guidelines
No, follow-up ultrasound is not routinely needed for scattered areas of fibroglandular density on mammogram. Scattered fibroglandular density is a normal finding that represents the normal distribution of glandular and fibrous tissue within predominantly fatty breasts [ 1 ]. This is a common breast composition pattern and is not considered suspicious or abnormal. It does not require additional imaging unless there are other concerning findings on the mammogram such as a mass, asymmetry, architectural distortion, or suspicious calcifications.
Key Points to Consider
- Scattered fibroglandular density is simply a description of breast tissue composition and indicates that the breast is composed of approximately 25-50% glandular tissue, with the remainder being fat [ 1 ].
- This level of density has minimal impact on the sensitivity of mammography for detecting breast cancer.
- If your mammogram report mentions only scattered fibroglandular density without any other abnormal findings, routine screening as recommended by your healthcare provider is appropriate.
- The American College of Radiology (ACR) recommends that breast density be reported in every mammogram report as either fatty, scattered, heterogeneously dense, or extremely dense [ 1 ].
Recommendations for Screening
- Women with scattered fibroglandular density should follow routine screening guidelines as recommended by their healthcare provider.
- Supplemental screening with ultrasound or other modalities may be considered for women with dense breast tissue or other high-risk factors, but this is not routinely recommended for women with scattered fibroglandular density [ 1 ].
From the Research
Diagnostic Performance of Imaging Modalities
- The diagnostic performance of mammography, ultrasound, and MRI for breast cancer detection has been compared in various studies 2.
- Mammography has been shown to have a lower sensitivity (54.5%) compared to MRI (94.6%) and ultrasound (67.2%) 2.
- The combination of MRI, ultrasound, and mammography has been found to increase diagnostic ability, with a sensitivity of 97.7% 2.
Breast Density and Cancer Risk
- Breast density, particularly fibroglandular density, is a known risk factor for breast cancer 3.
- Studies have shown that women with dense breasts are at a higher risk of developing breast cancer, and that the glandular tissue component (GTC) is independently associated with future breast cancer risk 4.
- The GTC has been found to have an inverse association with lobular involution, and women with a moderate or marked GTC are at a higher risk of developing breast cancer 4.
Role of Ultrasound in Breast Cancer Screening
- Ultrasound has been shown to be a useful modality in breast cancer screening, particularly in women with dense breasts 2, 4.
- However, the addition of ultrasound to mammography and MRI has been found to have negligible benefit in terms of sensitivity and specificity 5.
- Ultrasound may be useful in evaluating the glandular tissue component and background parenchymal enhancement, which are associated with breast cancer risk 4, 6.
Follow-up Ultrasound for Scattered Areas of Fibroglandular Density
- There is limited evidence to suggest that a follow-up ultrasound is necessary for scattered areas of fibroglandular density on a mammogram.
- However, studies have shown that the glandular tissue component and background parenchymal enhancement are associated with breast cancer risk, and that ultrasound may be useful in evaluating these factors 4, 6, 3.