Solitary intradural extramedullary metastasis of renal cell carcinoma to the conus medullaris

We report the case of a 68-year-old man with a 6-year history of renal cell carcinoma (RCC), who presented with severe low backache and paraparesis for a month before admission. In addition, he experienced urinary retention for 2 weeks. A spinal magnetic resonance imaging scan revealed the presence of an intradural extramedullary solitary mass at the conus medullaris. We performed a laminectomy and completely excised the tumor. The histopathological findings were suggestive of spinal metastasis of RCC. After the operation, the patient did not complain of backache and urinary retention, and paraparesis improved significantly. Spinal metastases of RCC are usually extradurally located. Intradural metastases of RCC are rare. Thus far, only six cases of RCC metastasizing to the cauda equina have been reported; however, RCC metastasis to the conus medullaris has not yet been reported. Conus medullaris lesions may cause symmetrical motor and sensory deficits accompanied by early autonomic system impairment. Surgery is the treatment of choice in cases of resectable RCC metastases, especially in cases of solitary metastasis.

摘要此篇文章中我們報告一個已知超過六年腎臟細胞癌病史的68歲的男人，他承受後背劇痛及下肢無力一個月的時間。 另外，他亦有約二個星期尿液滯留的現象。 脊髓核磁共振顯露了一個硬膜內脊髓外脊髓圓錐位置上的腫塊。接著椎板切除後腫瘤被完全地去除了。 組織病理檢查結果是腎臟細胞癌的脊髓轉移。 手術後患者腰疼和尿液滯留的症狀消失了，並且下肢力量也得到極大的改善。 腎臟細胞癌的脊髓轉移通常出現在硬膜外，然而腎臟細胞癌硬膜內的轉移是罕見的。至今，僅六個個案報告腎臟細胞癌轉移至馬尾；但尚未報告腎臟細胞癌轉移至脊髓圓錐處。本個案報告發現：脊髓圓錐處的腎臟細胞癌轉移可能表現出對稱的運動和感覺缺乏及自主神經系統的早期的損傷症狀。手術是腎臟細胞癌轉移到脊髓圓錐處治療的選擇，特别是單一的癌轉移。