Anterior cranial base glioneuronal heterotopia

Abstract

Cranial base glioneuronal heterotopia is a nest or linear array of glioneuronal tissue within the basal meninges. It is thought to arise from aberrant migration of embryonic neuroepithelial tissues into the subarachnoid space. It frequently mimics tumors and may extend through basal skull bones into extracranial soft tissues. We describe a case of intracranial anterior skull base leptomeningeal glioneuronal heterotopia in a newborn female who was diagnosed in the prenatal period by ultrasound examination to have an intracranial space-occupying lesion at 35 weeks of gestation. There was no evidence of increased intracranial pressure at birth. Magnetic resonance imaging showed a large, predominantly solid, minimally enhancing tumor in the anterior cranial fossa extending into the suprasellar region as well as into the right and left middle fossae. The gross tumor was totally resected through bifrontal craniotomy. Although uncommon, diagnosis of intracranial extracerebral glioneuronal heterotopia should be strongly ascertained while evaluating intracranial space-occupying lesions during the prenatal period and infancy. It needs to be distinguished histologically from teratoma and primary central nervous system tumors. Prenatal screening for early diagnosis of the lesion is vital. The location of the lesion and its relationship to the surrounding structures should lead to an accurate diagnosis in the majority of cases. Complete resection is curative and should be the goal. Long-term prognosis is excellent in view of the benign nature and extraaxial origin of the lesion.