Metaplastic Carcinoma of the Breast: MRI Features with Clinical and Histopathologic Correlation

Rationale and Objectives: Metaplastic carcinoma of the breast (MCB) is a rare type of breast carcinoma, and there are only limited data about the MRI findings of MCB. This article aimed to review the MRI features of MCB and correlate the MRI findings with clinical and histo-pathologic characteristics. Materials and Methods: A total of 23 patients were enrolled from a signal institution. The clinical data, histological diagnosis and MRI findings were retrospectively reviewed. Results: The average age of the 23 patients was 51.6 years. Twenty-one (91.3%) patients presented with a palpable mass. Squamous cell carcinoma was the most common subtype (10/23, 43.5%). Axillary lymph node metastasis was detected in 4 (17.4%) patients. The immu-nohistochemical profile showed the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor-2 (Her-2) expression were negative in 87.0%, 95.7%, and 91.3% of the patients respectively. On MRI, most cases exhibited an irregular mass (18/ 23, 78.3%) with high signal intensity on T2-weighted images (22/23,95.7%), non-circumscribed margin (19/23, 82.6%), heterogeneous enhancement (13/23, 56.5%), Type III (12/23, 52.2%) time intensity curve, and diffusion restriction (20/23, 87.0%) on diffusion weighted images (DWI). Conclusion: MCB most commonly demonstrated definitely malignant MRI features, which may reflect the histopathologic characteristic of this rare and aggressive breast carcinoma.