Phyllodes tumors are rare biphasic tumors of the breast. The stromal component may show homologous and heterologous sarcomatous elements, including osteosarcomatous differentiation. Here we report a 63 year-old lady who presented with a right breast lump diagnosed as a malignant phyllodes tumor showing predominantly osteosarcomatous differentiation with clinicopathological features.
Keywords: Phyllodes, tumor, breast, osteosarcoma