A 70 year-old man with recently diagnosed myelodysplastic syndrome presented with a one-month history of severe progressive asymmetric flaccid paraparesis, sensory loss, and bladder and bowel dysfunction. MRI of the cervical and thoracic spine demonstrated two T2-hyperintense lesions in the thoracic spinal cord and conus medullaris; gadolinium enhancement was initially absent but subsequently present in the spinal cord lesions and cauda equina. Lumbar puncture revealed 2 total nucleated cells/mcL, protein 76 mg/dL, 0 oligonclonal bands, and IgG index 0.6. Spinal fluid cytology, infectious, and paraneoplastic autoantibody evaluation, and serum aquaporin-4 IgG and myelin oligodendrocyte glycoprotein IgG antibodies were negative. No dural arteriovenous fistula was present on MR angiography. Given the onset, severity, and imaging features, the patient was treated empirically with IV methylprednisolone followed by plasma exchange therapy while awaiting remaining workup.
Given an inadequate treatment response, further evaluation with body PET-CT revealed two indeterminate subcutaneous lesions. Excisional biopsy of one lesion demonstrated CD20 positive B-cell aggregates within the lumen of small blood vessels, consistent with intravascular lymphoma. Methotrexate, rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy was initiated. After two rounds of chemotherapy, the patient’s strength improved to antigravity bilaterally.