Breast ImagingE2323. Extramammary Malignancies Enountered in Breast Imaging
Mason K, O'Brien S, Kunjummen J. Emory University, Atlanta, GA
Address correspondence to k. Mason (email@example.com)
Background Information: The main goal of screening and diagnostic breast imaging is to diagnosis primary breast cancer of mammary tissue origin. However, although rare, there are certainly other pathology findings including malignancy that may be encountered during these examinations. Other malignancies found in the breast include lymphoma, primary soft tissue neoplasms, and metastatic disease. Using different imaging modalities, it is the job of the radiologist to recognize extramammary malignant disease to help guide further management and treatment. This educational exhibit will attempt to demonstrate the different types of extramammary malignancies, their radiologic findings with histopathologic correlation, and the importance of recognition.
Educational Goals/Teaching Points: The goals of this exhibit are to review the different types of primary and metastatic extramammary malignancies found in breast imaging and discuss their imaging findings with histopathologic correlation. Metastatic disease to the breast represents less than 2% of breast malignancies. In approximately 12–31% of cases, metastases to the breast were the first sign of metastatic disease; thus underscoring the importance of recognition that may dictate management. Metastatic disease is most commonly found as a palpable breast mass; however, the second most common method of detection is on screening mammogram. Imaging characteristics of metastatic disease vary depending on the type of primary cancer as well as the pathway in which the cancer spreads. The most common imaging finding is a single mass, and calcifications are rare. Primary extramammary malignancies may also arise in the breast. Examples of soft tissue neoplasms include: angiosarcoma, rhabdomyosarcoma, liposarcoma, adenocystic sarcoma and Kaposi sarcoma. Lymphoma with secondary involvement of the breast is much more common than primary breast lymphoma, which represents less than 0.5% of cases. Different types of extramammary malignancies are more common in certain patient populations. For example, radiation-induced angiosarcoma occurs in up to 2% of patients who have undergone breast conservation therapy.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques: We review imaging characteristics of metastatic disease encountered in breast imaging with examples including melanoma, lymphoma, and head and neck cancers with histopathologic correlates. We also review imaging characteristics of primary malignancies arising in the breast with examples including sarcomas (Kaposi, adenocystic, and liposarcoma) and lymphoma with histopathologic correlates.
Conclusion: The Centers for Disease Control and Prevention reported over 12 million mammograms were performed or ordered in 2012. Given that the second most common method in which metastatic breast cancer is found is during screening mammography, it is vital that the radiologist be informed and aware of the varying ways in which metastatic disease to the breast may present. Although more rare, primary cancers of soft tissue and blood may also arise in the breast, further emphasizing the importance of understanding the imaging findings across different modalities.