Agenesis of the corpus callosum with interhemispheric cyst.

The radiographic features of a cerebral malformation are presented. The major findings are absence of the corpus callosum, a large interhemispheric cyst, and ventricular dilatation. This cerebral dysplasia originates in the first trimester of fetal development resulting in gross psychomotor deficiencies and seizure disorders. Diagnosis which depends predominantly on encephalographic or ventriculographic findings enables formulation of a guarded prognosis.