Isolated late intradural cauda equina metastasis of renal cell carcinoma

BACKGROUND: The cauda equina (CE) is the most common site for intradural extramedullary metastasis from systemic malignancies such as lung, breast, and thyroid carcinomas. However, renal cell carcinomas (RCC), with their high metastatic potential, are rarely responsible for CE metastatic lesions. Here, we report an intradural cauda equina mass, as the first and only site of metastasis of a renal cell carcinoma. CASE DESCRIPTION: A 55-year-old female had undergone a left nephrectomy for renal cell carcinoma 8 years ago. She now presented with a unifocal renal cell metastasis to the CE. As such metastases are rare, establishing the correct pathological diagnosis proved to be a challenge. CONCLUSION: The cauda equina was the first and only site of an 8-year-delayed metastasis attributed to a renal cell carcinoma.