A Case of Phyllodes Tumor with Focal Transition into Low-Grade Lymphangiosarcoma

Summary Background: Phyllodes tumors are fibroepithelial neoplasms that are extremely rare, comprising less than 1% of all breast neoplasms. Malignant transformation may occur, usually within the stromal component of the phyllodes tumor. The most common patterns of stromal malignancy are fibrosarcoma and myxoliposarcoma. Other patterns include chondrosarcoma, osteosarcoma and leiomyosarcoma. Case Report: Here, we report the case of a 42-year-old female patient who had a borderline phyllodes tumor with focal transition into a low-grade lymphangiosarcoma. The patient was treated with mastectomy and sentinel lymph node biopsy which showed no metastatic spread to the axilla. No further adjuvant treatment was given, and the patient remains free of recurrent disease 9 months after surgery. Conclusions: To the best of our knowledge, this is the first report of a malignant transformation of a borderline phyllodes tumor