RESUMEN
We report a case of recurrent breast cancer with solitary lung metastasis that has shown no recurrence with treatment by trastuzumab alone after partial resection of the right lung upper lobe. A 56-year-old woman, who presented with left breast cancer, underwent quadrantectomy and axillar lymph node dissection in March 2004. Pathological findings were as follows: invasive ductal carcinoma, 3. 7 cm in size, histological grade 3, positive invasion of lymphatic and blood vessels, negative nodal status, negative ER/PgR status, and overexpression of HER2/ neu. She had received adjuvant radiotherapy followed by cyclophosphamide, methotrexate and fluorouracil combination chemotherapy; however, a lung nodule developed 14 months after first operation, which had grown gradually. Partial resection of the lung with thoracoscope assistance revealed metastatic lung cancer from breast cancer. Trastuzumab treatment for 6 months after second operation has maintained no recurrence for 4 years.