Excerpt
Breast metastasis from an extramammary primary tumor is a rare phenomenon. Although primary breast cancers are the most commonly diagnosed cancer in women, metastasis to the breast only accounts for 1.3% to 2.7% of all breast malignancies.1 The most common sources of primary tumors are hematopoietic neoplasms, malignant melanomas, and lung carcinomas.2 There have been fewer than 500 documented cases in the last century, with most being single case studies.