Metaplastic breast carcinoma showing undifferentiated spindle cell component resembling fibrosarcoma. Other foci had high-grade chondrosarcoma (same case as the previous three images). The center of the image shows entrapped benign ducts. Prognosis: Given that metaplastic breast carcinomas are a heterogenous group of tumors, the prognosis varies depending upon the specific subtype present. Low-grade spindle cell carcinomas (fibromatosis-like) have a relatively favorable outcome with low-risk of recurrences and distant metastases. Carcinosarcomas and matrix-producing metaplastic breast carcinoma, on the other hand, are highly aggressive tumors. They often present at higher stages and usually require mastectomy and chemotherapy.