Squamous cell lung carcinoma metastatic to the breast.

Secondary malignancy metastatic to the breast is uncommon with an incidence of 0.5% to 3% of patients with extramammary malignancy. Here, an intriguing, rare case with metastasis to the breast from squamous cell lung carcinoma is reported. A 48-year-old women suffered from chronic cough with sputum for two months. The histological diagnosis, a achieved by bionchoscopic biopsy was squamous cell lung carcinoma. Concurrent chemoradiation therapy was given. Unfortunately, a left breast lump was noted eight months later and metastatic squamous cell lung carcinoma to the breast was diagnosed by surgical biopsy. Secondary malignancy metastatic to the breast is uncommon, yet this entity does exist. In view of the therapeutic implication, a metastatic breast lesion should not be mistaken for a primary breast carcinoma. Only with the awareness of such a possibility can prompt diagnosis and optimal treatment be achieved.