Phyllodes Tumor
A fibroepithelial breast tumor characterized by a prominent stromal component. While it shares some histologic features with fibroadenomas, phyllodes tumors have much higher malignant potential.
1. Histological Hallmarks
| Feature | Description |
|---|---|
| Leaf-like Structure | Hypercellular stroma that forms characteristic leaf-like projections into ductal spaces. |
| Stromal Component | Significant stromal overgrowth with atypical, pleomorphic cells and increased mitotic activity. |
2. Exam Must-Knows
- Epidemiology: Typically occurs in older women (40s–60s), contrasting with the younger demographic of fibroadenomas.
- Clinical Behavior: Can be benign, borderline, or malignant. The malignant form is highly aggressive and prone to local recurrence and hematogenous spread.
- Management: Unlike small fibroadenomas, phyllodes tumors usually require wide surgical excision to minimize the high risk of local recurrence.
Pathology Board Hint: For boards, use the buzzwords “leaf-like” and “stromal overgrowth”. If a question presents a breast mass that looks like a fibroadenoma but is occurring in a 50-year-old or is significantly larger/rapidly growing, you must suspect a Phyllodes tumor.