Whether phyllodes tumors are benign, borderline, or malignant, the treatment is the same: surgery to remove the tumor, along with at least 1 centimeter of surrounding healthy breast tissue. Some doctors feel that an even wider margin of healthy tissue should be removed. This approach is sometimes called "wide excision."

Wide excision is important because studies have shown that when wide excision is not done, phyllodes tumors are more likely to recur (come back) in the same area of the breast....