Bilateral breast metastases of a renal carcinoma: a case report and review of the literature.

Metastatic tumours account for <1% of all breast malignancies, most originating in the contralateral breast. An 88-year-old woman presented with bilateral breast lumps 4 years after radical nephrectomy for a T2N0M0 renal cancer. Mammography showed a circumscribed 15 mm mass just below and medial to the left nipple without any micro-calcification. Ultrasound scan showed the presence of a solid vascular mass in the left breast; a guided core biopsy confirmed it as a metastatic renal cell carcinoma. Left simple mastectomy and excision of right breast lump was done. Histology of both lesions confirmed them as metastatic deposits. Bilateral breast metastasis from a renal cancer is very rare and this is the second reported case. This case illustrates the potential for rare sites of metastases and for the consideration of metastasis in the presence of previous renal cancer. Recognition as metastatic neoplasm is important to prevent unnecessary radical procedures.