This is a rare congenital lesion characterized by the presence of fatty deposits in inappropriate places in the central nervous system The embryological derangement that leads to the formation of lipomas is still debated; lipomas are variously considered to be the result of mesodermal inclusion due to dysraphism, hyperplasia of normal leptomeningeal fat cells, heterotopia of displaced dermal anlage or derivatives from the embryological meninx primitiva(most accepted theory). Common locations are pericallosal, quadrigeminal cistern, hypothalamic suprasellar and cerebellopontine regions usually asymptomatic but can present with seizures, headache and behavioural disturbances. can be associated with callosal abnormalities. Pericallosal lipoma is usually located within the interhemispheric fissure along the corpus callosum , and on the basis of MR imaging findings in adults and children, these lesions are classified as one of two types . The tubulonodular form is round, more than 2 cm in size, and is usually located at the genu area of the corpus callosum. The second form, on the other hand, is curvilinear; thin and elongated, it is less than 1 cm in diameter and is usually found more posterior to the corpus callosum. The former has ben more associated with callosal anomalies association with pericallosal lipomas include midline defects (cleft lip or palate, median cleft nose, hypertelorism, cerebellar vermis defects, frontal lipomas) and dysraphism (myelomeningocele, encephalocele, anomalies of the cervical spine, cranium bifidium, or other calvarial defects).
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