Teaching NeuroImages: Intradural, intramedullary spinal cord metastasis from primary renal cell carcinoma

A 75-year-old man with hypertension presented with 2 weeks' history of left lower extremity numbness and weakness. Initial neurologic examination revealed 4/5 muscle strength in the left lower extremity with intact reflexes and decreased left-sided sensation. MRI of the thoracic spine revealed a mass with surrounding edema at T11–12 (figure 1, A and B). CT chest, abdomen, and pelvis showed left renal mass (figure 1F). Biopsy showed stained cells, positive for PAX8 and vimentin and negative for glial fibrillary acidic protein, which was consistent with renal cell carcinoma (figure 2). The patient underwent surgical excision and radiotherapy. Intradural intramedullary metastatic lesions are a rare manifestation of primary renal cell cancer.1,2