Cystosarcoma phyllodes, Cystosarcoma phylloides, Phylloides tumor

Phyllodes tumors (from Greek : phullon leaf), also cystosarcoma phyllodes, cystosarcoma phylloides and phylloides tumor, are typically large, fast-growing masses that form from the periductal stromal cells of the breast. They account for less than 1% of all breast neoplasms.
       .Phyllodes tumors are a fibroepothelial tumour composed of an epithelial and a cellular stromal component. They may be considered benign , borderline, or malignant depending on histologic features including stromal cellularity, infiltration at the tumor's edge, and mitotic activity. All forms of phyllodes tumors are regarded as having malignant potential. A large series from the M.D. Anderson Cancer Centre reported the incidence of each as benign (58%), borderline (12%), and malignant (30%). Malignant phyllodes tumours behave like sarcomas and can develop blood-borne metastases. Approximately 10% of patients with phyllodes tumours develop distant metastases and this can go up to 20% in patients with histologically malignant tumours. The commonest sites for distant metastases are the lung, bone, and abdominal viscera. Rare sites of metastasis like to parotid region have also been described.