From the Guidelines
Yes, breast asymmetry is common on screening mammograms after significant weight loss, such as 150 pounds. When a person loses a substantial amount of weight, breast tissue often changes unevenly between the two breasts, leading to asymmetry that may be visible on mammographic imaging. This occurs because breast tissue is composed of both glandular tissue and fat, and weight loss primarily affects the fatty component. The distribution of fat loss can vary between breasts, resulting in differences in size, density, and appearance. Additionally, the supporting structures of the breasts, including Cooper's ligaments, may be affected differently by weight loss, contributing to asymmetrical sagging or repositioning of breast tissue.
According to the most recent guidelines, patients who have experienced significant weight loss should inform their radiologist about this history when undergoing mammography, as it provides important context for interpreting any observed asymmetry 1. While breast asymmetry following weight loss is typically benign, any new or concerning asymmetry should still be evaluated thoroughly to rule out underlying pathology. The American College of Radiology (ACR) recommends that mammography is the first-line imaging modality for evaluation of pathologic nipple discharge, and it is also useful in the evaluation of breast asymmetry 1.
Some key points to consider when evaluating breast asymmetry on a screening mammogram after significant weight loss include:
- The patient's history of weight loss should be taken into account when interpreting the mammogram results
- Breast asymmetry can be a normal finding, but it should be evaluated thoroughly to rule out underlying pathology
- Mammography is the first-line imaging modality for evaluating breast asymmetry, and additional views such as spot compression and magnification may be needed to better evaluate the subareolar region
- Ultrasound may also be used to evaluate breast asymmetry, especially if the mammogram results are inconclusive or if there are suspicious findings.
It is essential to note that while breast asymmetry following weight loss is typically benign, any new or concerning asymmetry should still be evaluated thoroughly to rule out underlying pathology. The ACR recommends that any highly suspicious breast mass detected by imaging or palpation should undergo biopsy unless there are exceptional clinical circumstances 1.
From the Research
Breast Asymmetry on Mammograms After Significant Weight Loss
- Breast asymmetry can be detected on a screening mammogram, and it is defined as an area of increased density in one breast compared to the corresponding area in the opposite breast 2.
- Asymmetries are often benign or caused by summation artifacts due to typical breast tissue superimposition during mammography, but they can also indicate breast cancer 2.
- A study found that asymmetric breast tissue was present in 3% of mammograms, and breast cancer was diagnosed in two patients, but it was associated with a palpable abnormality 3.
- Developing asymmetries, which are new or increased in conspicuity compared to previous mammograms, are challenging to evaluate and should be viewed with suspicion because they can be an uncommon manifestation of breast cancer 4, 5.
Weight Loss and Breast Asymmetry
- There is limited research on the specific relationship between significant weight loss, such as 150 pounds, and breast asymmetry on mammograms.
- However, a study found that higher body mass index (BMI) was associated with slightly increased odds of follow-up after an abnormal screening mammogram, but the actual differences in days to follow-up across BMI groups were small and unlikely to be clinically significant 6.
- It is essential to note that breast asymmetry can be a normal variation, and not all cases require further evaluation or biopsy 3.
- If a developing asymmetry is detected on a mammogram, diagnostic mammography, sonography, breast magnetic resonance imaging, or biopsy may be recommended to determine the cause 2, 4, 5.