Phyllodes tumors of the breast are rare tumors that start in the connective (stromal) tissue of the breast. They get their name from the leaf-like pattern in which they grow (phyllodes means leaf-like in Greek). They are most common in women in their 30s and 40s, although women of any age can be affected.

Where are Phyllodes found?

Phyllodes tumors grow in the connective tissue of your breast, called the stroma. The American Cancer Society says that most phyllodes tumors aren't cancerous, so they don't often spread outside your breast. However, they can grow quickly.

What are Phyllodes?

Phyllodes (fil-oy-deez) tumors are a rare form of breast tumor; they can be benign (not cancerous), malignant (cancerous), or borderline (having characteristics of both). Phyllodes tumors account for fewer than 1% of all breast cancers.