Lipoma of the corpus callosum associated with frontal and facial anomalies.

Seven patients with a corpus callosum lipoma associated with a frontal cranial defect with or without a superficial lipoma or a fronto-nasal dysplasia, were encountered over a period of 12 years. This group of patients is reported as these associated lesions may provide a lead to the cause of lipomas of the corpus callosum as well as of the different lesions in the fronto-facial region. From our experience and that of others, the frontal lesion may be an extracranial lipoma, a frontal bone defect, with or without an external lipoma, a lipomeningocele connecting the extracranial lipoma through a frontal defect with the corpus callosum lipoma, a frontal encephalocele. Fronto-nasal dysplasia associated with a corpus callosum lipoma, seems to form an independent group although some of these patients may have other extracranial lesions as well. It is suggested by the authors that as the primitive mesenchyme gives rise to the meninx primitiva as well as to the fronto-facial skeleton a disturbance of the neural crest may give rise to these combined lesions. Further analysis of similar cases may indicate the timing of these events, and perhaps reveal a common causative factor.