Abstract
INTRODUCTION: Primary tumors of the breast containing bone and cartilage are extremely rare, and an osteogenic sarcoma arising from a cystosarcoma phyllodes is exceptional. CASE PRESENTATION: A 40-year-old Indian woman presented with a breast mass which was diagnosed as osteosarcoma of the breast on biopsy. Our patient was treated with a simple mastectomy after excluding the presence of skeletal primary and extra-mammary metastases. Final pathology showed a cystosarcoma phyllodes with signs of osteogenic sarcoma. CONCLUSION: Although osteogenic sarcomas of the breast are rare, they need to be distinguished from carcinosarcomas and metaplastic carcinomas as the management of the two differ.