Phyllodes Tumor of the Breast in Pregnancy and Lactation.

Phyllodes tumor constitutes around 1% of all and 2.5% of fibroepithelial breast lumps. Three types including benign, borderline, and malignant tumors have been described. The benign variant is the most common, is close to fibroadenoma, but is usually larger and recurs more frequently. The rare malignant type is aggressive. Standard treatment consists of lumpectomy with appropriate margins for benign phyllodes tumor, while the borderline and malignant variants must be treated by wide resection or mastectomy. Phyllodes tumor is a rare tumor in pregnancy and lactation, and the effect of gestational alterations in hormone levels on this tumor have not been discussed in the literature, except for several case reports. In summary and alluding to our recent literature review, large size, fast growth, bilaterality, and probably malignancy are more commonly expected in gestational phyllodes tumors.