Breast metastasis from a colonic adenocarcinoma: a case report and literature review

Metastasis to the breast from extramammary tumors are uncommon and metastatic colon carcinoma (MCC) to the breast is extremely rare. A case history is presented of a 42 year-old woman with a finding of a breast lump. One year before, she had undergone an anterior colon resection for a rectal carcinoma. Mammographic examination revealed a high density, well demarcated, 3 cm lesion located in the upper outer quadrant of left breast, along with smaller multiple bilateral nodules. Following breast biopsy, the final diagnosis of MCC was based on the absence of any precursor lesion within the breast (no surrounding ductal carcinoma in situ) and of the expression of cytokeratin 20 and beta-catenin on immunohistochemistry. The treatment strategy for metastatic breast disease is based on a proper assessment of such cases by surgeons, radiologists and pathologists.