Primary osteogenic sarcoma of the breast.

Primary osteogenic sarcomas of the breast are extremely rare with less than 100 cases reported in literature. They generally present in middle aged and older women and are highly aggressive. These tumors need to be differentiated from osteoid/bone- producing metaplastic carcinomas as the two differ in their biologic behavior and treatment protocols. A 60-year-old lady presented with a short history of a rapidly enlarging breast lump. Histopathological examination revealed a richly cellular, pleomorphic tumor with abundant osteoid. The tumor cells were immunoreactive for vimentin and negative for cytokeratin and estrogen and progesterone receptors.