Classic illustrations of benign and malignant phyllodes breast tumors in two patients

Phyllodes tumors, World Health Organization fibroepithelial tumors, are classified as benign, borderline, or malignant based on histopathology. Phyllodes must be distinguished from benign fibroadenomas, also WHO fibroepithelial tumors. The distinction of phyllodes from fibroadenomas can be challenging clinically, as these tumors may mirror one another. Here, we present 2 cases, classic clinical and imaging examples of benign and malignant phyllodes, to review the current epidemiology, classification, diagnosis, and treatment of phyllodes tumors.