To highlight a case with intramedullary spinal cord tumor (IMSCT) mimicking Neuromyelitis-optica-spectrum-disorder (NMOSD) and to discuss features that should raise suspicion of a neoplasm in suspected inflammatory longitudinally-extensive-spinal-cord-lesions (LESCL).

LETM is defined as an inflammatory intramedullary lesion that extends over three vertebral segments or more. It is most commonly associated with NMOSD, however can be seen in neoplastic, infectious, vascular, or metabolic conditions among others.

A 37-year-old male with history of hypertension presented with one month of progressively worsening right leg weakness. On exam, he was noted to have diffuse hyperreflexia with pathologic upper motor neuron signs. MRI of cervical spine revealed long segment of expansive cord signal abnormality from C4 to T3 associated with enhancement concerning for NMOSD. MRI-Brain was unremarkable. There was no prior history of optic neuritis. He had coexisting disc protrusion predominantly at C5 with severe spinal canal narrowing and underwent cervical spine fusion. Repeat MRI established extension of the lesion beyond T2. His differential diagnosis was LETM from NMO versus a spinal tumor

CSF protein was elevated with negative OCB. Serum ACE and ANA were normal. Serum Antiaquaporin4-IgG-antibodies by ELISA was borderline positive at 4.1. He did not respond to a course of IV steroids followed by plasma exchange after 4 weeks. Repeat MRI of cervical spine showed worsening cord signal abnormalities with patchy enhancement concerning for IMSCT. Spinal cord biopsy was performed, and pathology revealed spinal cord ganglioglioma.

Ganglioglioma is a rare, slow-growing primary central nervous system (CNS) tumor which frequently affects the temporal-lobes, resulting in seizures accounting for 0.5% of all primary-CNS-neoplasms. Ganglioglioma of the spinal cord is exceedingly rare, with only 70 cases reported. Distinguishing between inflammatory and neoplastic causes can be challenging in patients with LESCL. A thorough work up including tissue biopsy is pivotal in diagnosing appropriately and directing management.