LIPOMA OF THE CORPUS CALLOSUM A CASE REPORT

1. LIPOMA OF THE CORPUS CALLOSUM A CASE REPORT M. SAIDI, Z. KHADIMALLAH, S. JERBI OMEZZINE, K. BOUSLAMA, K. MRAIDHA, HA. HAMZA Department of Medical Imaging, Tahar SfarUniversityHospital Center, Mahdia, Tunisia NR10

2. INTRODUCTION • Lipomas of the corpus callosum are rare congenital conditions. • These lesions are often asymptomatic but may present as epilepsy, hemiplegia, dementia or headache. • Computerized tomography and magnetic resonance imaging make the diagnosis of lipomas feasible at any site of the intracranial space.

3. CASE REPORT • An 18 months-old healthy boy presented at urgency with head injury. Axial CT scans with sagittal reconstructions were performed. • CT scans have revealed a low density inter-hemispheric lesion (-50 to -70 HU ) involving the corpus callosum from genu through the body into the splenium . • The Low-attenuation values indicative of fat within the lesion and the absence of calcification were suggestive of corpus callosum lipoma.

4. Axial and sagittal CT scans : Low density inter-hemispheric lesion with Low-attenuation values indicative of fat

5. DISCUSSION

6. CORPUS CALLOSUM ANATOMY • The corpus callosumis a wide, flat bundle of neural fibers beneath the cortex in the eutherian brain at the longitudinal fissure. • Theposterior portion of the corpus callosum is called the splenium; the anterior is called the genu (or "knee"); between the two is the truncus, or "body", of the corpus callosum. • The isthmus is The part between the body and the splenium • Therostrum is the part of the corpus callosum that projects posteriorly and inferiorly from the anterior most genu

7. Sagittal T1-weighted MRI of the brain shows the normal appearance of the corpus callosum.

8. CORPUS CALLOSUM FUNCTIONS • The corpus callosum is the largest white matter structure in the brain. • It connects the left and right cerebral hemispheres • It ‘s involved in several functions of the body including: • Communication Between Brain Hemispheres • Eye Movement • Maintaining the Balance of Arousal and Attention • Tactile Localization…

9. CORPUS CALLOSUM LIPOMA • Lipomas of the central nervous system are extremely uncommon in contrast to those arising elsewhere, and are estimated to comprise less than 0.1% of all intracranial tumors . • The majority of intracranial lipomas occur in the midline region and corpus callusum lipomas represents 30 to 50% of all intracranial lipomas. • It’s considered as a congénital brain malformation rather than a true neoplasm and it’s often associated with partial or complete corpus callosum agenesis

10. CLINICAL MANIFESTATIONS • A patient with this tumor is often asymptomatic, which is the case in our observation, and the locc is discovered accidently • Symptoms depends on associated malformations . • Patients may suffer from convulsions, mental retardation, motor disturbances, headaches, visual disturbances, vertigo and vomiting, Intracranial hypertension . • Epilepsy is one of the most frequent symptoms

11. DIAGNOSTIC IMAGING : CT • Computed tomography reveals a typical interhemispheric lesion of variable extent, depending on part or complete involvement of corpus callosum.. • Low-attenuation values indicative of fat (-50 to -100 HU) can be easily established within the lesion. • Curvilinear calcification has been consistently reported; however ; there was no calcification in our case. • The presence of calcifications , prospect differential diagnosis with dermoid cysts and teratomas, and the diagnosis of corpus callosum lipoma could not be certain.

12. DIAGNOSTIC IMAGING : CT Axial CT scan: interhemispheric hypodense area containing calcific component. Axial CT scan: low density inter-hemispheric lesion (-50 to -70 HU ). Neuroanatomy (2009) 8: 39–42

13. DIAGNOSTIC IMAGING : MRI • MR scans do not leave doubts, infact fat signal is characteristically hyper in T1w and T2w sequences, and in FATSAT sequences it is suppressed Axial and coronal MR scans: interemispheric area of hyperintensity in T1 and T2, it becomes hypointense in FS (fat saturation) sequences Neuroanatomy (2009) 8: 39–42

14. TREATEMENT AND EVOLUTION • There’s no indication to surgical treatment in isolated (pure) corpus callosum lesions; on the other hand, surgical outcomes are controversial because is difficult a complete debulking that spare the nervovascular structures involved • Prognosis and symptoms depends on associated malformations . • Risks to be considered, above all in the evolutive age, are hydrocephalus and epilepsy.

15. CONCLUSION • Intra-cranial lipomas are extremely rare brain tumors. Lipomas of corpus callosum constitute the commonest variety of all intra-cranial lipomas and are associated with varying degrees of dysgenesis of corpus callosum. • CT can make the diagnosis but MRI is a procedure of choice in the evaluation of corpus callosum lipomas and eventual associated malformations.