Metastasis of Pulmonary Carcinoma to the Breast: Case Report

Introduction: Pulmonary carcinoma is the most prevalent cancer in the world, followed by breast cancer. It has high mortality rates in men and women mainly due to its ability to metastasize. Metastases from lung carcinoma to the breast are extremely rare. The first case described occurred in 1965 and since then there are few cases of this condition reported in the world medical literature. Case report: A 59-year-old woman who complained of low back pain in May 2017. The investigation revealed a metastatic site in the fifth vertebra of the lumbar spine with unknown origin. Six months later, a new lesion was found in the ninth vertebra of the thoracic spine. Immunohistochemistry showed positivity for cytokeratin 7 and TTF1 markers, confirming the hypothesis of lung carcinoma as the primary site. In March 2018, the patient evolved with a symptomatic nodule in the right breast on ultrasound and with positivity for TTF1 on immunohistochemical study, confirming the metastasis of lung carcinoma to the breast. Treated for two years until March 2020, when she presented multiple brain metastases. Patient had no therapeutic success and died. Conclusion: The difficulty in diagnosing lung carcinoma metastasis to the breast stands out, surgeons, clinicians and pathologists should consider this diagnosis, although rare.