[A case of 19th year pulmonary metastasis after radical mastectomy for breast cancer].

A 72-year-old woman was admitted to our hospital for further evaluation of a abnormal shadow in left middle lung field. The patient had undergone right mastectomy for infiltrating ductal carcinoma 19 years ago. She had no symptom, but had a time of mass X-ray screening this year. Chest CT finding showed a nodule 2 cm in diameter with slight irregular margin in S6 of left lung. We couldn't determine preoperatively that this tumor was a metastatic lesion or a primary lung cancer. And first, tumor was taken out for intraoperative frozen section diagnosis. Pathologist didn't diagnose whether this tumor was a metastatic or primary. So, we performed left lower lobectomy and mediastinal lymphadenectomy. On postoperative histopathologic finding lung cancer resembled well previous breast cancer. In immunohistochemical study cancer cells from lung and breast of the patient were respectively positive for anti Estrogen Receptor (ER) and anti Gross Cystic Disease Fluid Protein-15 (GCDFP-15). In conclusion lung cancer was diagnosed as a metastatic lesion from breast cancer 19 years ago. The patient has been well 2 years postoperatively without recurrence. In this case immunohistochemical examination was very useful for differentiation metastatic lesion and primary one.