Infiltrating Tumor versus Demyelination Disorders: Case Study of Two Adults

Abstract Long-segment intramedullary spinal cord lesions pose a unique diagnostic and therapeutic dilemma from a neurosurgical perspective. For the operating surgeon, the central challenge lies in distinguishing infiltrative intramedullary tumors from inflammatory demyelinating pathologies, as both may mimic each other clinically and radiologically. This distinction is critical: while early biopsy or decompressive surgery may be warranted for progressive neoplasms, unnecessary intervention in demyelinating disorders can result in avoidable morbidity in an already high-risk spinal cord environment. This report details two diagnostically challenging adult cases encountered in neurosurgical practice—one ultimately proven to be a astrocytoma, IDH-wildtype, CNS WHO grade 3 requiring definitive surgical management, and the other a neuromyelitis optica spectrum disorder (NMOSD) masquerading as a spinal cord tumor. By comparing their clinical progression, operative considerations, intraoperative neurophysiology, radiological subtleties, and final diagnoses, we highlight key decision points that influence whether to operate, observe, or pursue advanced immunologic testing. The aim is to provide neurosurgeons with a practical reference when faced with similar long-segment intramedullary lesions, underscoring the profound impact that early diagnostic accuracy has on surgical planning, neurological outcomes, and long-term patient quality of life.