Phyllodes tumors of the breast

UNCOMMON BREAST neoplasms, phyllodes tumors, occur in the same age group as breast carcinomas. The clinical behavior and morphologic features of these cystosarcomas have caused confusion in terminology, morphologic diagnosis, and clinical management. Clinically and mammographically, phyllodes tumors resemble a fibroadenoma, the most common fibroepithelial breast tumor. Histologically, phyllodes tumors show both epithelial and stromal components and their arrangement is somewhat similar to fibroadenoma. Criteria to separate benign from malignant cases are not well established in the literature, but the majority have a benign clinical course. Only 35% of histologically malignant phyllodes tumors show metastases. Accepted treatment is wide local excision. If the lesion is large and replaces a large portion of the breast tissue, a simple mastectomy is recommended.