AM Rahalkar, MD Rahalkar
Dept. of Radiology, Sahyadri Hospital, Plot No. 30 C, Erandwane, Karve Road, Pune 411004, India
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|Date of Submission||05-Apr-2006|
|Date of Acceptance||10-Aug-2006|
| Abstract|| |
Agenesis of corpus callosum can be associated with a midline lipoma ( LoCC ) with or without calcification of its periphery. LoCC may extend into either or both lateral ventricles. This developmental abnormality has an embryological basis. We observed this in 2 cases, and, as this is uncommon, are reporting them.
Keywords: Intra-cranial lipomas, Corpus callosum agenesis with midline lipoma, Lipoma of choroid plexus, CT and MR of lipoma of choroid plexus
|How to cite this article:|
Rahalkar A M, Rahalkar M D. Case report : 2 cases of lipoma of corpus callosum (LoCC) associated with lipoma of choroid plexus ( LoCP ). Indian J Radiol Imaging 2006;16:719-21
|How to cite this URL:|
Rahalkar A M, Rahalkar M D. Case report : 2 cases of lipoma of corpus callosum (LoCC) associated with lipoma of choroid plexus ( LoCP ). Indian J Radiol Imaging [serial online] 2006 [cited 2020 Jan 26];16:719-21. Available from: http://www.ijri.org/text.asp?2006/16/4/719/32331
| Introduction|| |
LoCC is a very rare anomaly, that can be associated with varying degrees of dysgenesis of corpus callosum. To see that this lipoma is entering into the lateral ventricle to be seen as LoCP is even more rare.To appreciate its presence on CT the radiologist has to change the viewing conditions to differentiate more hypodense fat from less hypodense CSF.
| Case Material|| |
Two cases are presented. Case 1 was a 27 year old, married woman, who was sent for investigation of epilepsy. On clinical and neurological examination no abnormality was seen. CT and MR images are given as [Figure - 1],[Figure - 2],[Figure - 3],[Figure - 4]. Case 2 was a 2 year old male child, who was also sent for investigation of epilepsy. CT images are given as [Figure - 5] and [Figure - 6]. Both showed agenesis of corpus callosum, tubulonodular LoCC and LoCP.
| Discussion|| |
Intra-cranial lipomas are extremely rare, comprising 0.1 to 0.5 of all primary brain tumours. LoCCs constitute the commonest variety of all intra-cranial lipomas (40 to 50 %) and are associated with varying degrees of dysgenesis of corpus callosum .
The origin of agenesis of corpus callosum has been explained in different ways by different workers . It arises as a result of mal-development or persistence of primitive meningeal tissue (meninx primitiva). During normal foetal development this meninx fills the potential cisterns in the embryonic brain and is resorbed to create sub-arachnoid spaces. Failure of this process and mal-differentiation of meninx results in the development of mature adipose tissue replacing its space. This mature adipose tissue may be present at multiple locations, thus explaining the presence of lipomas in multiple cisterns. Therefore, the lipomas of brain are mal-formations rather than a true neoplasm. The normal sub-arachnoid nerves and vessels may also become incorporated in these lipomas. This process occurs during first trimester, most probably between 3rd and 5th weeks of intra-uterine life.
As mal-development of primitive meninx occurs before the development of the inter-hemispheric commissural fissures, there is a frequent association of agenesis of corpus callosum with LoCC.
The development of lateral ventricular choroid plexus includes invagination of a portion of the inter-hemispheric cistern and tela choroidea of the ependymal roof plate through the choroidal fissure with infolding of the primitive meninx ,. The developing choroid plexus is attached to it and thus enters into the ventricle as well. In the absence of corpus callosum , LoCC would use the same path to enter into the lateral ventricles. This explains the association of LoCC with LoCP in some cases.
The incidence of association of LoCC with LoCP is variable. It has been reported to be 20 to 50 % ,.
In about 50 % of cases detection of LoCC is incidental. The patients may present with seizures, headache, emotional lability, hemiparesis or intellectual disorder. Both of our patients were investigated for epilepsy.
Both patients had classical features of agenesis of corpus callosum, viz, high riding third ventricle, separated and parallel lateral ventricles, colpocephaly and spoke wheel appearance of sulci over medial surface of cerebral hemispheres.
Both had a large, tubulonodular midline lipoma having characteristic CT value of fat. The second patient had also curvilinear calcification of lateral walls of the lipoma.
Both had extension of LoCC into right lateral ventricle through a narrow neck of choroid fissure to appear as a LoCP. The continuity was easier to be appreciated on MR because of hyperintense nature of fat on T1WI in contrast to hypointense CSF, while it requires to use wide windowing to appreciate slightly more hypodense fat from less hypodense CSF.
In the case No.1 a small LoCP was also seen on left without any connection with the LoCC. This may be still considered to be due to original continuation but subsequent loss and segregation from the main lipoma.
There have also been reports of isolated LoCP. A Uchino  reported a single case, while R N Sener  reported 7 cases, out of which 5 were adults and 2 were children. All these were isolated LoCP located in the trigone and not associated with any anomaly of corpus callosum or LoCC.
These 2 cases highlight the following features : 1) LoCC associated with corpus callosum agenesis can extend into either or both lateral ventricles through choroid fissure to appear as LoCP, 2) the connection between the two may get lost and as such an isolated LoCP may appear, 3) to appreciate the fat from CSF in the lateral ventricle may require change in the windowing, and 4) to appreciate the continuity or connection between the two lipomas MR is superior to CT.
| References|| |
|1.||Shah J, Srinivasa P, Gala B, Patkar D, et al. Multiple intracranial lipomas, hypogenetic corpus callosum and vestibular Schwannoma : an unusual spectrum of MR findings in a patient. J Postgrad Med 1999; 45(2): 53-55. |
|2.||Buxi TBS, Mathur RK and Doda SS. Computed tomography of lipoma of corpus callosum and choroid plexus lipoma: Report of two cases. J of Computed Tomography 1987; 11(1): 57-60. |
|3.||Yock DH Jr. Choroid plexus lipomas associated with lipoma of the corpus callosum. J Comput Assist Tomogr 1980; 4: 678-682. [PUBMED] |
|4.||Truwit CL, Williams RG, Armstrong EP. MR imaging of choroid plexus lipomas. Am J Neurology 1990; 11: 202-204. |
|5.||Uchino A, Hasno K, Matsumoto S, et al. Solitary choroid plexus lipomas : CT and MR appearance. AJNR 1993; 14(1): 116-118. |
|6.||Sener R N. Isolated choroid plexus lipomas. Comp Med Imaging and Graphics 1995;19(5): 423-426. |
A M Rahalkar
Dept. of Radiology, Sahyadri Hospital, Plot No. 30 C, Erandwane, Karve Road, Pune 411004
Source of Support: None, Conflict of Interest: None
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5], [Figure - 6]