An osteosarcoma arising from the breast tissue. The disease is Monarch Disease Ontology identifier MONDO_0004360 (breast extraskeletal osteosarcoma). Also known as: breast osteosarcoma, breast osteosarcoma (disease), osteogenic breast sarcoma, osteogenic sarcoma of breast, osteogenic sarcoma of the breast, osteosarcoma of breast, osteosarcoma of the breast.