What imaging is recommended for a breast lump in a breastfeeding woman?

From the Guidelines

For a breast lump discovered during breastfeeding, ultrasound is the recommended first-line imaging modality, as it is safe and effective in distinguishing between solid masses and fluid-filled cysts without radiation exposure. This approach is supported by the American College of Radiology's guidelines, which emphasize the importance of proper imaging to rule out malignancy, even though most breast lumps during lactation are benign conditions like galactoceles, plugged ducts, or mastitis 1.

Key Considerations

• Ultrasound is preferred for its ability to differentiate between solid and cystic masses without exposing the patient to radiation, making it ideal for lactating women.
• If ultrasound findings are concerning or inconclusive, a diagnostic mammogram may be considered, despite the potential challenges in interpreting mammograms due to the density of lactating breast tissue.
• MRI might be used as a supplementary tool, particularly if cancer is suspected, though this may require temporary interruption of breastfeeding due to contrast agents.
• It is crucial for the radiologist to be informed about the patient's breastfeeding status to ensure accurate interpretation of the images.
• The guidelines from the American College of Radiology, as outlined in the study by diFlorio-Alexander et al. 1, provide a framework for the appropriate use of imaging modalities in lactating women, emphasizing the role of ultrasound as the initial imaging modality.

Clinical Application

• The choice of imaging modality should be guided by the patient's age, the characteristics of the breast lump, and the clinical suspicion of malignancy, as outlined in the guidelines for palpable breast masses 1.
• However, for lactating women, the primary concern is to balance the need for accurate diagnosis with the safety and well-being of both the mother and the infant, making ultrasound the preferred initial imaging modality due to its safety profile.

From the Research

Imaging Modalities for Breast Lumps in Breastfeeding Women

• The primary imaging modality for evaluating palpable breast masses in breastfeeding women is ultrasound (US) 2.
• US has been shown to be effective in detecting malignancies in lactating women, with a sensitivity of 100% and a specificity of 70% 2.
• Mammography may not be necessary for breastfeeding women, as it can increase false-positive findings without adding any additional cancer diagnoses 2.
• Fine-needle aspiration cytology (FNAC) and core needle biopsy (CNB) are also useful diagnostic tools for breast lumps, with CNB being more accurate than FNAC 3.
• The diagnostic accuracy of FNAC and mammography can vary, with FNAC showing higher sensitivity and specificity in some studies 4.

Diagnostic Performance of Imaging Modalities

• Targeted US has a high negative predictive value (100%) and a moderate positive predictive value (9.4%) for diagnosing breast malignancies in lactating women 2.
• Mammography has a lower sensitivity (82.76%) and specificity (90.36%) compared to FNAC (97.22% sensitivity and 99.46% specificity) in diagnosing breast lumps 4.
• CNB has a higher diagnostic accuracy (93.4%) compared to FNAC (75.7%) in evaluating palpable breast masses 3.

Clinical Considerations

• The evaluation of palpable breast masses in breastfeeding women should be individualized, taking into account the patient's age, clinical presentation, and imaging findings 5.
• A thorough clinical breast examination, imaging, and tissue sampling are necessary for a definitive diagnosis of breast cancer 5.
• The use of US as the primary imaging modality can help reduce the need for unnecessary biopsies and mammography in breastfeeding women 2.