Imaging Findings of Metaplastic Carcinoma of the Breast with Pathologic Correlation

Objectives: To review the imaging findings of a series of cases of metaplastic carcinoma of the breast, a rare and aggressive form of breast cancer with variable imaging features. Materials and methods: Retrospective review of multimodality imaging features of eleven cases of metaplastic carcinoma of the breast retrieved from a single hospital institution database. Clinical and pathologic data were also documented. Results: The median age of presentation was 65 years. Four cases had axillary lymphadenopathies, and two had distant metastases. An oval mass was the most common sonographic finding (7/11; 64%). Lesions displayed circumscribed/partially circumscribed margins (6/11; 55%) or non-circumscribed margins (5/11; 45%). Most lesions had a heterogeneous echo structure (9/11; 82%) and posterior acoustic enhancement (6/11; 55%). In nine patients, mammographies were available. An oval dense mass was the most common mammographic finding (5/9; 56%). The majority of cases had non-circumscribed margins (6/9; 67%), and nearly half displayed calcifications (4/9; 44%). Conclusions: Mammographic findings were not different from the usual features of more prevalent types of breast cancer, though the majority of metaplastic carcinoma of the breast showed possible distinctive sonographic features, such as circumscribed margins or complex echogenicity, reflecting the histologic background.