Agenesis of corpus callosum with interhemispheric lipoma

In addition to complete absence of corpus callosum, the MRIs show a large, inverted, U-shaped lipoma that is hyperintense on sagittal T1-weighted (A) and uniformly hypointense on fat-saturated T2-weighted (B) MRIs. Transverse axial FLAIR images show widely spaced lateral ventricles bordering the hyperintense interhemispheric lipoma. When the corpus callosum is absent, the bodies of lateral ventricles are straight, parallel, and away from the midline. Interhemispheric lipoma is almost always associated with hypo- or agenesis of the corpus callosum.