corpus callosum – lipoma
the lipoma of the corpus callosum is a benign congenital lesion, accounting for 0.03% of all intracranial tumours. it can occur within the genu, body or splenium of the corpus callosum. its aetiology is unknown, but may involve defective rostral neurulation (association with frontal and midline facial dysraphic conditions) or inappropriate differentiation of primitive meningeal cells to form mature adipose tissue (other intracranial lipomas are found in subarachnoid sites).
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.
other fatty intracranial tumours include dermoids and teratomas, but the corpus callosum is an uncommon site for either.
echogenic midline intracranial mass, which may partially or completely replace the corpus callosum.
associated facial midline or frontal anomalies in 50%.
- corpus callosum lipoma-facial polyps
- jeanty p, zaleski w, fleischer ac prenatal sonographic diagnosis of lipoma of the corpus callosum in a fetus with goldenhar sydnrome am j perinatol 8: 89-90
- mulligan g, meier p lipoma and agenesis of the corpus callosum with associated choroid plexus lipomas j ultrasound med 8: 583-588
- christensen ra, pinckney le, higgins s, miller ke sonographic diagnosis of lipoma of the corpus callosum j ultrasound med 6: 449-451
- lin kl, wang hs, lui tn sonographic diagnosis of a corpus callosum lipoma with extracranial extension in an infant j ultrasound med 14: 537-541