Clinicopathological features of primary osteosarcoma of the breast

Objective To explore the clinicopathological features,differential diagnosis,therapy and prognosis of primary osteosarcoma of the breast. Methods A case of primary breast osteosarcoma was studied by microscopy and immunohistochemistry,and the literature was reviewed. Results There was no specificity about clinical symptoms and auxiliary examination. Histopathological examination revealed that the tumor was composed of spindle,oval or polygonal cells with abundant osteoid. Multinucleated osteoclastic cells were also seen. Immunohistochemical staining indicated that the tumor cells and multinucleated osteoclastic cells were positive for vimentin and CD68,respectively,but they were both negative for epithelial markers,estrogen and progesterone receptors and Her-2. Conclusion Primary osteosarcoma of the breast confirmed by pathology is extremely rare. Surgical removal is the most and best treatment,with optional pure mastectomy or modified radical mastectomy.