Introduction: Breast and renal carcinomas are common malignancies, with an increasing number of well-tolerated targeted therapies.

Case Report: We describe a case of concurrent, synchronous, metastatic breast and renal carcinomas where diagnosis was achieved after biopsy of two incongruous metastatic sites. The patient has been successfully treated with targeted therapies, exemestane and sunitinib, and later anastrozole and pazopanib, with radiological improvement and resolution of symptoms.

Conclusion: Literature review of cases of antecedent, synchronous and metachronous breast and renal cancers (multiple malignancies), did not reveal increased risk of developing renal cancer after breast cancer, or of breast cancer after renal cancer. Cases of multiple breast and renal cancers appear to occur at any time with out clear reasons for their occurrence. This case demonstrates the importance of appropriate investigation and accurate diagnosis of synchronous malignancies in patients who may be candidates for treatment targeted therapies. As clinical experience of concurrent use of targeted therapies grows, including trials for potential additive benefits of using targeted agents in combination, we will be able to offer improved treatment options for patients with both single and multiple malignancies.

Keywords: Multiple malignancies, Targeted therapies