Sunday, 1 January 2012

Corpus callosal Lipoma

Axial non contrast CT study brain shows a fat density along inter hemispheric fissure.
The mid line sagittal T1w image show a curvilinear type of lipoma along corpus callosum.
Role of MRI in this case is to rule out any associated Corpus callosal anamoly.
Corpus callosum is normal.

Related post :
Meckel's Cave Lipoma
Lipoma at incisura

Intracranial lipoma 

Syn : Lipomatous hamartomas, as normally fat not present in CNS.
A congenital malformation , not true neoplasm.
Contributes < 0.5% of all intracranial tumors.
A focal fat density (dark 'z' black) on CT or fat signal intensity (white on T1w image) and is often out standing in the background of adjacent normal grayish brain parenchyma.
Noted as an isolated incidental finding or as part of an associated anomalies. Most common anomaly associated is Corpus callosal agenesis or dysgenesis.

Most common location is supra tentorium ~80%. In that most common location is mid line along corpus callosum ~ 50%, Suprasellar cistern attached to infundibulum, hypothalamus ~ 20%,  Pineal region ~15%. Meckel's cave and lateral fissures are rare locations.
Infra tentorium contributes remaining 20%, in that common locations are Cp angles, jugular foramen and foramen magnum.

Two types of intracranial lipoma:
1. Curvilinear type is a thin stripe along CC.
2. Tubulonodular type is a bulky nodular mass, frequently show dense nodular calcifications, and often associated with Corpus callosal or adjacent parenchymal anomalies.

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