Micrograph of a phyllodes tumor (right of image) with the characteristic long clefts and myxoid cellular stroma. Normal breast and fibrocystic change are also seen (left of image). H&E stain.
Phyllodes tumors (from Greek: phullon), are a rare type of biphasicfibroepithelial mass that form from the periductal stromal and epithelial cells of the breast.[1] They account for less than 1% of all breast neoplasms.[2] They were previously termed cystosarcoma phyllodes, coined by Johannes Müller in 1838, before being renamed to phyllodes tumor by the World Health Organization in 2003.[3]Phullon, which means 'leaf' in Greek, describes the unique papillary projections characteristic of phyllodes tumors on histology.[1] Diagnosis is made via a core-needle biopsy and treatment is typically surgical resection with wide margins (>1 cm), due to their propensity to recur.[4]