Atretic encephaloceles are rare malformations resulting in herniation of meninges and the brain through an opening in the skull. They are thought to be in the spectrum of defects of neural tube closure. The etiology is unknown.

Atretic encephaloceles occur most commonly in the parietal, occipital, or frontal region and may present with an otherwise benign-appearing subcutaneous nodule or mass. Alopecic lesions over the defect can occur as well. They have been associated with intracranial anomalies including interhemispheric cysts, abnormalities of the corpus callosum, ventriculomegaly, cystic malformations, and venous anomalies.

Related topic: encephalocele