ABSTRACT
Phyllodes tumors are fibroepithelial lesions and malign forms are rare neoplasms with lower than 1% of all primary breast tumors. Malign forms are usually behaves like sarcomas because they occur in the stroma of the breast. Also proliferation of epithelium occurs and even it is less often, the epithelial component of phyllodes tumors can transform into malignancy too. This epithelial malignancies are usually in the form of infiltrative carcinomas and non-invasive tumors arising in benign phyllodes tumors are much rarer but can be seen. Literature include very few cases about this situation and cases are usually old woman. We report a 19-year old patient who was diagnosed with ductal carcinoma in situ arising in benign phyllodes tumor of the breast.