Objective: The purpose of this study was to evaluate the imaging features--including the mammographic, sonographic, MRI, and bone scintigraphic findings--in 12 patients with metaplastic carcinoma with chondroid differentiation of the breast and to correlate the imaging findings with the pathologic features.
Conclusion: Metaplastic carcinoma with chondroid differentiation of the breast manifests as a palpable mass and should be included in the differential diagnosis of a large indistinct highdensity mass with amorphous or coarse calcifications on mammography and a relatively circumscribed complex echoic mass with posterior enhancement on sonography. A relatively circumscribed mass with a nonenhancing T2 intermediate- to high-signal-intensity internal component on MRI and an area of intense uptake of 99mTc methylene diphosphonate (MDP) on bone scintigraphy might be useful in suggesting the diagnosis of metaplastic carcinoma with chondroid differentiation.