Cerebral lipoma and the underlying cortex of the temporal lobe: pathological features associated with the malformation

Abstract

Intracranial lipomas are believed to be congenital malformations rather than true neoplasms, resulting from the abnormal differentiation of the meninx primitiva, the undifferentiated mesenchyme. We report here the surgical pathological features of a lipoma that was located on the cerebral surface of an abnormally formed fissure, and the underlying cortex of the middle temporal gyrus of a 20-year-old woman. The mass was composed of typical adipose tissue in which a large number of blood vessels were present. Thick connective tissue associated with the arachnoid membrane covered the cortical surface. The cortex exhibited a polymicrogyric configuration in which the cortical ribbon was abnormally undulated and excessively folded. Reelin-immunolabeled Cajal-Retzius-cell-like cells were observed frequently in the fused molecular layer. The cortical lamination underlying the molecular layer was poorly defined. Along the border between the connective tissue and cortical surface, there was a narrow zone in which the mesenchymal and neuronal tissues were intermingled, and where immunohistochemical and ultrastructural investigations disclosed disruption of the basal lamina, prominent astrocytosis, and abundant axonal and synaptic profiles. These findings suggest that focal disturbances in cerebral cortical development occur in association with the development of lipomas.

Interhemispheric Osteolipoma with Agenesis of the Corpus Callosum

“…Lipomas occur preferentially along the midline and within the subarachnoid cisterns. Intracranial lipomas occur most frequently in the interpeduncular-, cerebellopontine angle-, sylvian-and prepontine cisterns 10,18) , and interhemispheric lipoma is the most common type.…”

5‐year Old Male With an Interhemispheric Frontal Mass

“…In terms of the histological assessment, this case showed typical features of a mature lipoma intermingled with neuroglial tissue imparted by the presence of neuropil showing reactive astrocytes and mature neurons with glial satellitosis. Reports of lipomas arising in that location with or without agenesis of the corpus callosum are not abundant and most of the lesions described are composed only of typical mature lipomatous tissue; (12) and these lesions are usually sharply demarcated from cortex, (10) or but others may show myelo‐lipomatous differentiation (i.e., with hematopoietic elements).…”

Interhemispheric Lipoma, Callosal Anomaly, and Malformations of Cortical Development: A Case Series

“…Intracranial lipomas are rare congenital malformations, which are composed of adipose tissue and are considered to be a result from the abnormal persistence and maldifferentiation of the primitive embryonic meninx, the mesenchymal precursor of the leptomeninges, during development of the subarachnoid cisterns. [1][2][3][4] Common locations of intracranial lipomas include the deep interhemispheric fissure, quadrigeminal cistern, prepontine cistern, and sylvian cistern. 3,5 They are rarely found on the surface of the cerebral cortex.…”

“…3,5 They are rarely found on the surface of the cerebral cortex. 1,2,[5][6][7] The most common type of intracranial lipoma is the interhemispheric lipoma. Interhemispheric lipomas tend to be located above the corpus callosum, typically seen as either large and lobulated lipomas in the anterior callosal region or thin and curvilinear in the posterior callosal region.…”

“…8 Interhemispheric lipomas are frequently accompanied with hypogenesis or agenesis of the corpus callosum. 1,2,8 They, however, may less frequently be associated with malformations of cortical development (MCD). We present magnetic resonance imaging (MRI) findings of three infants with an interhemispheric lipoma, callosal anomalies, and cortical developmental abnormalities.…”