A rare case of a borderline phyllodes tumor with simultaneous intraductal and infiltrating duct carcinoma is reported. The patient was a 52-year-old woman with a breast tumor detected by physical examination. A simple mastectomy was performed. The excised tumor had a macroscopic appearance of a phyllodes tumor. After histological examination, the diagnosis of ductal carcinoma within a borderline phyllodes tumor was made. Immunohistochemical staining revealed that the epithelial component was positive for Epithelial Membrane Antigen and cytokeratin. No metastasis was detected in the axillary lymph nodes and the patient didn't receive any adjuvant therapy. No recurrence or metastasis has been observed 38 months after the surgery.
Keywords: Breast carcinoma; Intraductal carcinoma; Phyllodes tumor.