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

BACKGROUND: 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. OBSERVATIONS: 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. LESSONS: 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.