Renal cell carcinoma intraspinal metastases: a peripheral nerve sheath tumor mimic. Illustrative case

Renal cell carcinoma (RCC) metastases to the spinal cord, cauda equina, nerve root, and dorsal root ganglion (DRG) are rare and can mimic benign peripheral nerve sheath tumors.

A PRISMA-guided review of the PubMed/MEDLINE, Scopus, Embase, and Google Scholar databases identified 47 studies consisting of 57 patients with intradural extramedullary (IDEM), intramedullary spinal cord, or nerve root/DRG RCC metastases. The mean age was 59.4 ± 12.4 years, 71.9% were male, and clear cell RCC was the most common subtype (59.6%). Lesions involved intramedullary spinal cord metastasis in 57.9%, IDEM disease in 31.6%, and primary nerve root/DRG metastases in 10.5%. IDEM and nerve root lesions most often caused pain and radiculopathy, whereas intramedullary lesions uniformly produced myelopathy or motor weakness and more frequent sphincter dysfunction. Surgery was performed in 71.9% of patients, with gross-total resection in 80.5% of operative cases. The illustrative case was a symptomatic left C6-7 foraminal mass with focal Ga-68 DOTATATE uptake and progressive radiculopathy with mild left upper extremity weakness that mimicked schwannoma but was confirmed intraoperatively as metastatic RCC; resection and stabilization achieved durable symptom resolution.

New foraminal or dumbbell-shaped lesions in patients with malignancy warrant tissue diagnosis to guide appropriate metastasis-directed management. https://thejns.org/doi/10.3171/CASE26244.