Dec 28, 2025 9:52:51 PM
Breast density plays a significant role in breast cancer detection and surgical planning. In patients with dense breast tissue, tumors can be more difficult to identify on imaging, making accurate tumor localization essential. This article explains what breast density is, how it affects imaging and localization, and how modern localization strategies support safe and precise surgery.
What Is Breast Density?
Breast density refers to the proportion of fibroglandular tissue compared to fatty tissue in the breast and is assessed on mammography. It is typically classified into four categories, ranging from almost entirely fatty to extremely dense.
Dense breast tissue appears white on mammograms, similar to many breast tumors. This similarity can obscure malignancies and reduce the sensitivity of mammographic screening. According to the American Cancer Society, dense breast tissue can mask cancers and may also be associated with a slightly increased risk of breast cancer.
How Breast Density Affects Cancer Detection
In women with dense breasts, mammography alone may not provide sufficient diagnostic confidence. Tumors can blend into the surrounding tissue, particularly when lesions are small or non-calcified.
To improve detection, additional imaging is often used, including:
- Ultrasound for identifying masses not visible on mammography
- MRI for high-risk patients or complex diagnostic cases
- Targeted imaging based on clinical findings
A review published on PubMed shows that multimodality imaging significantly improves detection rates in dense breasts.
Challenges of Tumor Localization in Dense Breasts
When tumors are difficult to visualize, accurate localization becomes critical for surgical success. Palpation is often unreliable, and imaging landmarks may be limited, particularly after biopsy or neoadjuvant therapy.
This makes localization tools essential to ensure that the correct tissue is removed. For a general overview of localization techniques, see Breast Cancer Localization.
Imaging Modalities Used in Dense Breasts
The choice of imaging modality depends on breast density and tumor characteristics:
- Mammography remains first line but is less sensitive in dense tissue
- Ultrasound helps localize lesions obscured on mammography
- MRI offers superior contrast resolution and is particularly useful in dense breasts or invasive lobular carcinoma
More detail on MRI-based workflows is available in MRI-guided localization in breast cancer.
Markers and Localization After Biopsy
When imaging visibility is limited, clip markers placed during biopsy become essential reference points. These markers preserve the location of the original lesion, even if it later becomes indistinct.
You can read more about biopsy-related markers in Breast Biopsy Devices.
Before surgery, the clip is often targeted with a localization marker to guide resection. Options include wire-guided localization, radioactive seeds, and non-radioactive magnetic seeds. A comparison is available in Seed Localization vs Wire-Guided.
How Sirius Medical Supports Localization in Dense Breasts
Sirius Medical supports accurate localization in challenging imaging scenarios. The Pintuition Marker® is a non-radioactive magnetic seed that can be placed at the biopsy clip or tumor site. During surgery, the Pintuition System® provides real-time audio and visual guidance to help surgeons reach the target precisely.
This approach supports predictable surgery even when tumors are difficult to visualize preoperatively.
Want to learn more about localization in dense breast tissue?
Request a demo or explore our resources to learn how Pintuition® supports breast-conserving surgery.
Disclaimer
This article is intended for informational purposes only and should not be considered medical advice. Always consult a qualified healthcare professional.