Regarding the phyllodes tumor, all of the following statements are true, except:
Phyllodes tumours like fibroadenomas, arise from intralobular stroma, but are much less common. Majority of phyllodes tumors have MED12 mutations. HOXB13 protein overexpression was found to be correlated with stromal hypercellularity and atypia and may be implicated in the development of malignant phyllodes tumors. The larger lesions often have bulbous protrusions (phyllodes is Greek for "leaflike") due to the presence of nodules of proliferating stroma covered by epithelium. In some tumours these protrusions extend into a cystic space. Phyllodes tumor is distinguished from fibroadenoma on the basis of higher cellularity, higher mitotic rate, nuclear pleomorphism, stromal overgrowth, and infiltrative borders. Most phyllodes tumors present in the sixth decade, 10 to 20 years later than the peak age for fibroadenoma. Most have low-grade (benign) cytologic features. Regardless of grade, lymphatic spread is rare. The uncommon high-grade lesions give rise to distant hematogenous metastases in about one-third of cases. Only the stromal component metastasizes.
Intralobular stromal tumor
Overexpression of HOXB13 is associated with more aggressive clinical behavior
Most of these tumors are high grade
Metastasis of only the non-epithelial/stromal component
Breast