Abstract
We report a case of primary osteosarcoma of the breast, which is a rare histological type of all breast tumors. A 50-year-old woman was admitted to our hospital because of a rapidly growing tumor in her right breast. The serum level of alkaline phosphatase (ALP) and that of vascular endothelial growth factor (VEGF) were high. Since the elastic-hard tumor was about 22cm in size and was very easy to bleed, the patient underwent subemergency mastectomy and axillary lymph node dissection. Histopathologically, the tumor was diagnosed as osteosarcoma of the breast, which was considered to be derived from metaplastic carcinoma. The elevated levels of ALP and VEGF decreased after the surgery. Since the role of adjuvant chemotherapy is still unclear because of the limited data, radiation therapy was delivered postoperatively to the chest wall, with a total dose of 60 Gy. The patient has been free from recurrence of distant metastasis as of 4 months after the surgery.
