A case of breast carcinoma with cartilaginous and osseous metaplasia.

We report a case of a 49-year-old Japanese woman diagnosed with breast carcinoma with osseous and cartilaginous metaplasia with a poor outcome. Histological examination revealed invasive ductal carcinoma with undifferentiated sarcomatous components including chondrosarcomatous areas. Osseous metaplasia was also noted in a very limited area. Neither axillary lymph node metastases nor vessel invasion were observed. Immunohistochemical examination was negative for estrogen receptor, progesterone receptor and HER2 overexpression. Stage II A T2N0M0 carcinoma was diagnosed postoperatively. Five months after the operation, she developed lung metastases. Although she received systemic chemotherapy, the lesions increased in number and grew rapidly. She died of pulmonary distress 5 months after relapse.