RESUMEN
Both fibrocystic change and phyllodes tumor are classified as fibroepithelial tumors of breast which are composed of epithelial and stromal components. Although as the most common benign breast lump fibrocystic lesions are known by symptom such as pain, nipple discharge, heaviness, usually in women's third decade of life, mammographic and sonographic features often render them almost indistinguishable from phyllodes tumor. In view of the essential differences in terms of therapeutic planning which exist between these two tumors, their early and precise distinction is crucial to avoid problem such as patients' anxiety and unwarranted tumors operation. In this article a case of fibrocystic change in a 24 year old woman is reviewed in which clinical signs and symptoms and mammographic changes are indication of phyllodes tumor