Pulmonary Adenocarcinoma Presenting as Bilateral Triple Negative Breast Cancer: Case Report and Literature Review

Abstract

The vast majority of breast malignancies are primary lesions. However, metastasis to the breast is unusual with melanoma and hematolymphoid malignancies being the most common. In addition, metastasis from lung cancer to breast can occur, with adenocarcinoma being the most common histological subtype to metastasize. We report a 77-year-old female who presented with bilateral breast lesions, initially was thought to be bilateral mammary carcinoma, after thorough imaging workup, it was diagnosed as secondary lesions from lung adenocarcinoma. This diagnosis was confirmed by proper immunohistochemical and molecular studies on the bilateral breast biopsies. The patient was managed by tyrosine kinase inhibitors and responded well. Identification of primary versus secondary breast lesions is a very essential step in inpatient management as treatment lines can differ entirely. Performing a proper immunohistochemical panel is essential in such cases to make this differentiation in addition to the clinical and imaging correlation.