Metastases from renal cell carcinoma-Report of three unpredictable cases and literature review.

The capacity to metastasize after long periods of discovery and resection of the primary renal lesion or to present as metastasis with undisclosed primary lesions grant renal cell carcinomas (RCC) a formidable and unpredictable behavior. We report three unusual cases of metastasis from RCC. The first patient presented with metastatic clear cell adenocarcinoma in the right shoulder muscles, with unknown primary and revealed an undetected clear cell right RCC on radiology. The second patient presented with a hemorrhagic nasal metastasis of RCC. A history of nephrectomy for RCC, 10 years prior to the development of nasal metastasis was elicited. The third patient presented with axillary and later abdominal wall metastasis of papillary RCC. He had a history of RCC 3 years prior to the discovery of metastasis. RCC has the propensity to appear as a metastatic carcinoma with unknown primary, requiring exclusion of several diagnostic pathologic entities. The appearance of metastasis many years after disease quiescence is challenging and clinicians need to be sensitized to the need for long-term surveillance in RCC. Though the prognosis remains poor, immune checkpoint inhibitors are currently the modalities of choice in such cases.