Primary spinal oligoastrocytoma mimicking longitudinally extensive transverse myelitis

Longitudinally extensive transverse myelitis (LETM) is most commonly associated with neuromyelitis optica spectrum disorders (NMOSD). However, a wide range of etiologies may produce longitudinally extensive spinal cord lesions (LESCLs) on imaging. We highlight the case of a patient with a spinal cord tumor whose imaging showed LESCL and was diagnosed with LETM. He did not respond to immunosuppression and subsequently developed a progressive and protracted clinical course. Thoracic cord biopsy performed 6 years after symptom onset showed primary spinal oligoastrocytoma. We discuss the features that should raise suspicion of a neoplasm in the context of LESCL and serve a reminder that not all LESCLs are inflammatory.