Delineating Extramammary Findings at Breast MR Imaging

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Breast magnetic resonance (MR) imaging captures extramammary structures in the thorax and upper abdomen.
• Incidental extramammary findings in patients with a history of malignancy are more likely to be malignant.
• These findings can significantly impact cancer staging and treatment decisions.

Purpose of the Study:

• To review the frequency, distribution, and context of extramammary findings on breast MR images.
• To correlate these findings with known sites of breast cancer metastasis.
• To highlight clinically important nonmalignant findings and diagnostic pitfalls.

Main Methods:

• Systematic review of extramammary findings on breast MR images.
• Correlation with known distant sites of breast cancer metastasis (bone, lung, liver, lymph nodes).
• Discussion of unusual metastasis sites (gastrointestinal tract, peritoneum, adrenal glands) and nonmalignant findings.

Main Results:

• High-yield organ systems on breast MR images correlate with common sites of distant breast cancer metastasis.
• Malignant extramammary findings can involve the skin and chest wall, influencing staging.
• Unusual metastasis sites and clinically significant nonmalignant findings were identified.

Conclusions:

• A systematic approach is crucial for interpreting extramammary abnormalities on breast MR images.
• Understanding these findings improves diagnostic sensitivity and specificity.
• Accurate interpretation aids in appropriate diagnostic next steps and patient management.