Colorectal breast metastases presenting with atypical imaging features.

Breast metastases from non-breast primaries are rare in female patients and exceedingly rare in male patients, with only a handful of cases described. Lymphoma, metastatic melanoma and bronchial carcinoma are the primary sites for the majority of breast metastases. Breast metastases from colorectal carcinoma have been described previously in only a small number of cases in the literature. Here, we report a further two patients with biopsy-proven colorectal carcinoma metastases to both breasts, who demonstrate contrasting unusual and atypical imaging features that have not been reported previously. In one case, the imaging appearances mimic a multifocal primary breast carcinoma. Metastatic disease in the breast is a marker for disseminated metastatic spread, with a correspondingly poor prognosis. Therefore, we review the imaging features that differentiate metastatic breast disease from multifocal breast primaries, which are important to recognize because the management options for these patients differ greatly.