Neuroimaging features of multiple sclerosis in children can differ from the usual adult pattern. Frequently, lesions can be more larger and pseudo-tumoral with a variable evolution. The most critical differential diagnosis in childhood is with acute disseminated encephalomyelitis that is a relatively frequent acquired inflammatory disease of the white matter with a polymorphous appearance. Some differences between multiple sclerosis and acute disseminated encephalomyelitis in children such as distribution of white matter lesions and frequency of gray matter involvement should be pointed out. Neveretheless only follow-up examination can make the definitive diagnosis in the majority of the cases.