Magnetic resonance imaging of metaplastic carcinoma of the breast: sonographic and pathologic correlation.

Metaplastic carcinoma of the breast is a rare disease. We describe the MRI findings with the correlative sonographic and pathologic features of two cases. On MRI, T2-weighted images demonstrate a relatively well-defined mass with high signal intensity cystic components. Dynamic enhancement subtraction images showed an early enhancing and delayed washout peripheral rim and non-enhancing internal components. A microlobulated, isoechogenic mass with cystic components was seen sonographically, and was histopathology related to necrosis and cystic degeneration. Although these features are not unique, metaplastic carcinoma should be included in the differential diagnosis for breast masses.