Breast Contralateral Metachronous Cancer: Metastases or Second Primary Beast Tumor?

Breast contralateral metachronous cancer is relatively rare. Familial history, BRCA 1 and BRCA 2 mutations, histopathologic type, stage of primary neoplasia and hormone status, is considered risk factors for breast metachronous cancer. The differential diagnosis between a breast contralateral metachronous cancer and a distant metastasis from the primary tumor is difficult and a subject of debate in the literature. We present herein two cases with breast metachronous contralateral tumors; the first is considered as distant metachronous metastasis and the second case, as a second primary tumor. A literature review was also performed.