Supratentorial neurenteric cysts-A fascinating entity of uncertain embryopathogenesis

The histopathological, immunologic, and ultrastructural findings of neurenteric cysts support an endodermal derivation. These developmental cystic lesions are generally located in the posterior mediastinum, abdomen, and pelvis and may also contain some mesodermal and neuroectodermal elements. In contrast, neurenteric cysts of the central nervous system are very infrequent and occur most commonly in the spinal canal. Intraspinal neurenteric cysts are usually encountered in the cervicothoracic region with an intradural, extramedullary location and are commonly associated with congenital defects of the overlying skin and/or vertebral bodies. Intracranial neurenteric cysts are very uncommon and typically located in the posterior fossa. Several hypotheses have been postulated to explain the origin of intracranial neurenteric cysts. However, the embryologic basis of these fascinating lesions remains incompletely understood. Supratentorial neurenteric cysts are distinctly rare often represent a diagnostic challenge on preoperative neuroimaging. In fact, only 22 cases of supratentorial neurenteric cysts have been reported in the literature including our own patient with a laterally based convexity extraaxial cyst presenting with seizures. In this report, we review the clinical, radiographic, and histological findings of supratentorial neurenteric cysts. We discuss the differential diagnoses and surgical considerations in the management of these intriguing lesions. We also provide an extensive review of normal human embryogenesis and discuss putative mechanisms of embryopathogenesis of supratentorial neurenteric cysts.