What is a key growth characteristic of phyllodes tumors?

• A. Slow-growing
• B. Fast-growing
• C. Regresses spontaneously
• D. Only occurs in one breast

Answer: (B)

Phyllodes tumors are defined by their rapid, aggressive growth of the mass. They tend to enlarge quickly over weeks to a few months because the stromal component grows vigorously, which makes the lesion stand out clinically. This rapid growth helps distinguish them from fibroadenomas, which typically grow slowly and may remain stable for a long time, especially in younger patients. While phyllodes tumors can be benign, borderline, or malignant, the hallmark growth pattern remains their swift expansion. They’re usually unilateral, but the important characteristic for this question is the fast growth.