The coexistence of invasive ductal carcinoma and malignant phyllodes tumor with liposarcomatous and chondrosarcomatous differentiation in the same breast in a post-osteosarcoma case.

Malignant phyllodes tumors of the breast are rare biphasic neoplasms, the stromal component of which may show homologous and heterologous sarcomatous elements. Malignant epithelial transformation is rare. It has been reported in a few cases of in situ and infiltrating ductal or lobular carcinoma. Rarely, breast carcinomas and phyllodes tumors may also develop in the same breast independent of each other. To our knowledge, this is the first case of two different types of tumor occurring in the same breast at the same time in a post-osteosarcoma case.