Metastatic breast lump: A rare presentation of squamous cell lung cancer

Breast metastases from extramammary neoplasm are uncommon with an incidence of 0.5% to 3% of patients with extramammary malignancy. We reported an extremely rare case of breast metastasis from squamous cell lung carcinoma. A 60-year-old woman suffered from dry cough with shortness breath for one month with simultaneous development of breast lump. The histological diagnosis, achieved by bronchoscopic lung biopsy with the aid of immunohistochemistry was squamous cell lung carcinoma. Breast lump was a metastasis from lung, confirmed by histopathology and immunohistochemistry after core needle 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.