Abstract
Multiple sclerosis (MS) is a demyelinating disease of the CNS with an estimated incidence of 0.05-2.85 per 100,000 children. One subtype, tumefactive MS, is particularly rare and difficult to diagnose, especially in differentiating from tumor. We describe the case of a 16-year-old boy who presented with subacute onset of headaches, cognitive difficulties, dizziness, blurry vision, right arm weakness, numbness, and gait difficulty. MRI of the brain demonstrated a multilobulated, contrast-enhancing, T2 hyperintense area of diffusion restriction in the left frontal lobe, an extensive left periventricular lesion, and multifocal T2/fluid-attenuated inversion recovery hyperintense lesions. He clinically improved with IV steroids and a 1-month oral steroid taper, and then, 2 weeks after completion of the taper, he experienced recurrent headaches and cognitive decline. Repeat brain MRI (3T) with MS protocol which included 3D T2* gradient recalled echo was notable for lesions demonstrating central vein sign (CVS) and paramagnetic rim-like areas within the large left frontal lesion characterized by positive phase shift and associated contrast enhancement. Based on the presence of typical symptoms, multiple enhancing and nonenhancing lesions in the periventricular and juxtacortical regions, and 6 CVS-positive lesions, the patient met 2024 McDonald criteria, and the diagnosis of MS was made. The patient was treated with IV steroids followed by oral steroids and then started on ocrelizumab. This case demonstrates how recognition of CVS is critical, because early and accurate diagnosis enables timely treatment without unnecessary interventions.