Sarcoidosis is a benign systematic granulomatous disorder of unknown etiology and is associated with various malignancies. However, granulomatous and metastatic lymph node lesions are difficult to distinguish even when using precise and modern diagnostic methods, such as positron emission tomography. Thus, histological verification is the only method that can be used to accurately describe the nature of this disease. In this article, we report a case of non-luminal HER-2/neu-positive breast cancer in a patient without history of sarcoidosis and suspected to have metastatic disease.