Newborn with hydrocephalus on prenatal US

Head US of agenesis of the corpus callosum with a small interhemispheric cyst
Coronal US of the brain shows a Viking horn deformity of the anterior horns of the lateral ventricles (above left) and parallel bodies of the lateral ventricles (above right). There is mild hydrocephalus present and the third ventricle is high riding. Sagittal US of the brain (below) shows absence of the corpus callosum.

The diagnosis was agenesis of the corpus callosum with a small interhemispheric cyst.