A Case of Paraneoplastic NMOSD With Sarcoma and Unusual Cauda Equina Enhancement

Objective To describe a case of sarcoma associated with NMOSD presenting with myeloradiculitis. Background Neuromyelitis optica is a demyelinating disease of the CNS that predominantly affects the spinal cord and optic nerves. Reports of NMOSD occurring in the setting of cancer suggest that aquaporin-4 autoimmunity may have a paraneoplastic basis. Here, we describe a patient with metastatic sarcoma who tested positive for aquaporin-4 IgG consistent with NMOSD. Design/Methods 66-year-old man with left thigh soft tissue sarcoma with metastasis to the lungs admitted for 2-day history of urinary retention. Neurological exam showed bilateral lower extremity weakness, with decreased patellar reflexes. MRI spine showed cord swelling with enhancement from C6 downwards into the thoracic spine with associated syringohydromyelia and diffuse enhancement of the cauda equina. MRI brain was normal without abnormal enhancement in the optic nerves. CSF analysis demonstrated elevated protein and 0 oligoclonal bands. Was started on methylprednisolone 1 gram daily for 5 days empirically for transverse myelitis. Extensive serum and CSF workup for other causes of myelopathy including rheumatologic, infectious, and nutritional etiologies were unremarkable until NMO IgG antibody came back positive at 1:10000 titer. He had minimal clinical improvement after methylprednisolone course and so was started on plasmapheresis for five days. His weakness improved slightly but continued to have urinary retention. Discharged to a long-term acute care facility on prednisone 60 mg daily with intermittent bladder catheterization and plan for follow-up with Neuroimmunology. Results NA. Conclusions Myeloradiculitis has been reported with anti-MOG disease but is not a typical finding for NMO. We report this case to highlight this unusual finding. In addition, sarcoma is an uncommon cause of paraneoplastic syndromes and to our knowledge, this is the first report of sarcoma being associated with paraneoplastic NMOSD.