corpus callosum – lipoma

the lipoma appears as an echogenic midline intracranial mass in a location corresponding to the corpus callosum. this is best appreciated on a coronal or sagittal plane, although transverse views will readily demonstrate the lesion. discrete calcification is common but difficult to define on sonography due to the high echogenicity of the lipoma. in 50% of cases the lipoma is an isolated finding, and may partially or completely replace the corpus callosum. additional lipomas may be found within the choroid plexus. the predominant associated lesions are midline facial and frontal anomalies. frontal cutaneous lipomas and lipomeningoceles, hypertelorism, median cleft nose, cranium bifidum and encephaloceles are seen. cerebellar vermian aplasia and spinal myelomeningoceles have been reported, as have cardiac defects. reported genetic associations include trisomy 21 and goldenhar syndrome.