baló's concentric sclerosis in a girl with interesting presentation.

balo's concentric multiple scleroses (ms) is a rare demyelinating disease and a variant of multiple sclerosis. we report a case with interesting misleading clinical history and typical ri findings of balo disease. a 19-year-old girl presented with fever and left hemiparesis following dental procedure 15 days ago. on physical examination fever and left limbs forces loss were noted. on ct scan a hypodense mass like area, and in mri a low t1 and high t2, and flair concentric onion-like partial enhancement of mass in parieto-frontal periventricular white matter was detected. regarding the findings tumefactive ms, low grade glioma, lymphoma, and abscess and regarding the history of abscess formation were in differential diagnosis. after therapy and no improvement in clinical condition and mri findings during 2 months, the patient underwent stereotactic biopsy and tumefactive balo ms was revealed. after 4 months of intensive therapy, the patient was discharged with normal condition.