[Malignant subtype of cystosarcoma phyllodes with brain metastases]

Cystosarcoma phyllodes is an uncommon type of breast tumour. Benign, borderline, and malignant subtypes have been described. Central nervous system metastases of the malignant subtype of cystosarcoma phyllodes are rare and associated with poor prognosis. We report on a patient with malignant cystosarcoma phyllodes who developed metastatic disease six years after resection of the primary breast tumour. Partial regression of a brain metastasis was achieved using radiotherapy but the patient later died due to widespread metastatic disease which was uncontrollable by systemic chemotherapy. Because metastatic malignant cystosarcoma phyllodes are largely resistant to treatment, the most important objective is to provide optimal management of the primary tumour before dissemination occurs.