Metastasis of Colon Cancer to the Breast.

Breast metastases from extramammary neoplasms are extremely rare, and even more so is metastasis of colon cancer to the breast. Despite its rarity, metastatic disease to the breast is an important diagnostic issue because its treatment differs greatly from that of primary cancer. Proper diagnosis of this rare event requires an accurate clinical history, proper immunohistochemical workup, and a high level of suspicion.