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Description
An 8-year-old developmentally normal boy was brought to emergency following a fall from a bicycle on the road. He could not remember how he fell and regained consciousness in about 5 min. He had an abrasion on the right forearm and cheek. On neurological examination, he was fully conscious and alert with an orientation to time, place and person. There was no neurological deficit at the time of presentation in the emergency ward. The child was kept under observation. Two hours later, he experienced one episode of generalised tonic–clonic seizure which lasted for 3 min. Seizures were managed as per standard protocol. CT scan of the brain was done (figure 1), which showed a homogeneously hypodense midline lesion with a mean HU of −109 (fat) with bilateral ventricular and anterior subarachnoid extensions. A peripheral rim of calcification was evident.
MRI brain was done subsequently to look for other structural malformations (figures 2−4), which showed a well-defined mass lesion situated in the midline superior to the high riding third ventricle having homogeneous hyperintensity on T1-weighted sequences as well as T2-weighted sequences. Bilateral lateral ventricles were oriented parallel with dilatation of occipital horns and agenesis of corpus callosum. These findings confirmed the diagnosis of ‘tubulonodular pericallosal lipoma with corpus callosum agenesis’ which is the most common variety of pericallosal lipoma.1 2
The case was discussed with the paediatric neurologist and it was interpreted that corpus callosal lipoma would have incited the seizure and the child had a fall with the transient loss of consciousness. Neurosurgery consultation was sought and as seizures were controlled by drugs, no urgent surgical intervention was indicated. Neurosurgical intervention is generally not required and it should be limited depending on the patient’s symptoms, surgical feasibility, and associated malformations. 3 4 The patient was discharged on antiepileptics.
Learning points
Intracranial lipomas are extremely rare congenital malformation and account for 0.1–0.5% of all primary brain tumours. Pericallosal lipoma is the the most common variety of all intracranial lipomas (50%) and is associated with varying degrees of dysgenesis/agenesis of corpus callosum like our index case.
Pericallosal lipoma is of two types: tubulonodular type and curvilinear type. Tubulonodular type is characterised by a bulky mass that can be anterior or posterior in location, whereas, on the other hand, the curvilinear type is thin, long and often posterior in location. The tubulonodular type is more common.
Nowadays, majority of pericallosal lipomas are prenatally detected.
The radiographic findings (as described above) are very characteristic, and, therefore, pathognomonic.
Isolated pericallosal lipomas are generally benign, self-limiting or slow-growing and remain asymptomatic in most of the cases. The overall prognosis of the corpus callosum lipoma is good.
Footnotes
Contributors AY and JK both were involved in case management and diagnosis of the case. Both were involved in writing the manuscript and literature review. Both approved the final draft.
Competing interests None declared.
Patient consent Obtained.
Provenance and peer review Not commissioned; externally peer reviewed.