Recurrent phyllodes tumor of the breast transforming to a fibrosarcoma

Phyllodes tumors are fibroepithelial tumors of the breast, representing 2-3% of all fibroepithelial tumors, and < 1% of all breast tumors. Malignant transformation may occur usually within stromal component of phyllodes tumor. Careful characterization of the stromal compartment is critical, since it is the pathologic features of stromal cells that determine its malignant potential. Primary sarcomas of the breast are extremely rare and account for < 0.1% of all malignant tumor of the breast, of which the conversion of a phyllodes tumor to sarcoma of the breast is even very rare and only two cases have ever been reported. We present a case of recurrent phyllodes tumor of the breast transforming to a fibrosarcoma.