Fetal pericallosal lipoma: US and MR findings

We report a case of fetal pericallosal lipoma occurring at the anterior interhemispheric fissure and associated with agenesis of the corpus callosum. During targeted prenatal ultrasonography at 26 weeks' gestation, the lesion was seen as a highly echogenic mass. MR imaging performed at 35 weeks' gestation and during the postnatal period revealed a pericallosal fatty mass and agenesis of the corpus callosum.