Supplementary Material for: Rectal Carcinoma Metastatic to the Male Breast after 7 Years: Case Report

<i>Background:</i> Colorectal cancer metastasis to a mammary location is very rare. <i>Case Report:</i> A 38-year-old male, who had undergone anterior resection of an advanced rectal carcinoma 7 years earlier, presented with a right mammary mass. Core needle biopsy of the mass indicated cytology consistent with breast adenocarcinoma. After neoadjuvant chemotherapy and modified radical mastectomy, pathology identified the mass as rectal carcinoma. <i>Conclusion:</i> The authors highlight the difficulty of making an accurate diagnosis of rectal cancer metastasis to the breast of a male.