[An uncommon malignancy of the breast: dermatofibrosarcoma protuberans with fibrosarcomatous transformation (DFSP-FS)].

Dermatofibrosarcoma protuberans (DFSP) is a morphologically distinct dermal/subcutaneous fibrohystiocytic neoplasm seen mainly on the trunk and the proximal extremities, which generally is regarded as a low-grade or "borderline" neoplasm. Dermatofibrosarcoma protuberans is characterized clinically by locally aggressive growth and a high rate of local recurrence, but distant metastases and tumor-related deaths are very rare. DFSP in the breast is extremely uncommon. Immunohistochemically, DFSP is characterized by positive staining for vimentin and CD34. We present a case of a 65 years old female patient with a giant DFSP developed in the sight of several excised fibroadenoma and neurofibroma treated by radical mastectomy and axillary block-dissection. Perioperative hystological and immunohistochemical images demonstrate the characteristics of the giant nonphylloid sarcoma.