Breast metastases from a Renal Cell Carcinoma. A case report and review of the literature()

INTRODUCTION: Metastases to the breast from extra-mammary tumors are uncommon and few sporadic cases are reported in the international literature. An accurate differential diagnosis of secondary cancer is mandatory because both prognosis and treatment differ with respect to primary breast tumors. PRESENTATION OF CASE: We present the case of a 70-year-old woman with an isolated metastasis to the breast occuring 9 years after undergoing a nephrectomy for Renal Cell Carcinoma (RCC). Clinical examination revealed a palpable and mobile mass in the right breast with an enlarged ipsilateral axillary lymph node. Mammographic findings showed a dense, well circumscribed solid mass and the breast ultrasonography findings were those of a hypoechoic homogeneous solid nodule with no posterior attenuation but with prominent peripheral vascularity. A tru-cut biopsy was conclusive for a metastatic deposit by RCC. A whole-body CT scan showed no evidence of further recurrences. The patient underwent metastasectomy and exeresis of the papable lymphnode. DISCUSSION: In patients with former surgery for RCC, a diagnosis based on a preoperative biopsy allows to indicate the proper surgical treatment: in facts, as compared to primary breast tumors treatment, the rationale to pursue wide surgical margins is pointless in cases of metastases and, similarly, the biopsy of the sentinel lymphnode is void of sense due to the lack of its physiopathological prerequisite. CONCLUSION: We suggest to consider a micro-histological biopsy of any new breast lesion appearing in a patient with a history of treatment for RCC. Prompt diagnosis is necessary to choose the right treatment.