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

Background: Colorectal cancer metastasis to a mammary location is very rare. Case Report: 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. Conclusion: The authors highlight the difficulty of making an accurate diagnosis of rectal cancer metastasis to the breast of a male.