MRI in the mild type of mucopolysaccharidosis II (Hunter's syndrome).

We report imaging findings in a 3-year-old boy with the typical mild type of Hunter's disease. MRI revealed multifocal large cyst- or spindle-like areas of increased and decreased signal in the white matter, including the corpus callosum on T1- and T2-weighted images. The white matter showed high signal on T2-weighted images, isointense with cerebrospinal fluid on all other pulse sequences. To our knowledge, these appearances have not been reported in this disorder. Deposition of mucopolysaccharide and/or glycolipid and increase in fluid content seem to be responsible.