A Case of a Malignant Phyllodes Tumor in the Breast with Lymph Node Metastasis

A 52-year-old woman experienced right breast pain and detected a mammary tumor 6 months ago. She then noticed rapid enlargement of the tumor, which was suspected to be a borderline malignant phyllodes tumor. The tumor size was approximately 15 cm and presented with skin congestion but without infiltration. The tumor showed internal heterogeneous echo and rich blood flow signals on breast ultrasonography. Ultrasonography also showed swelling of the axillary lymph node. Lymph node cytology revealed the presence of atypical cells in the lymph node, and CT scan showed lymph node metastasis in the right axilla and no distant metastases. We performed mastectomy with lymph node sampling. Pathological examination of the specimens confirmed a malignant phyllodes tumor and a metastatic lymph node. One month later, a subcutaneous mass and multiple pulmonary nodules were identified on a chest CT scan. Chest wall irradiation(45 Gy)and chemotherapy were performed, but the number of pulmonary nodules, pleural effusion, and size of the subcutaneous mass continued to increase. Although she underwent another chemotherapeutic treatment, she died 5 months after the surgery. Thus, we report a case of a malignant phyllodes tumor with an extremely rare lymph node metastasis, which rapidly progressed even though multimodal therapy was performed.