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Nasal glial heterotopia is a rare, benign congenital lesion composed of ectopic mature glial tissue that is disconnected from the intracranial contents. It may present as a nasal mass at birth or in early infancy and is considered a form of neuroglial choristoma.

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Epidemiology

Rare (~1 in 20,000–40,000 live births)
Presents in infancy or early childhood
No sex predilection
Can be extranasal, intranasal, or mixed

Pathogenesis

Results from herniation of glial tissue during embryonic development that becomes sequestered from the brain due to failure of skull base closure
Unlike encephaloceles, NGH has no direct intracranial connection

![Embryopathogenesis of cerebral heterotopias. Schematic illustrates that cerebral heterotopias result from failed retraction of dural diverticula allowing aberrant neurological tissue to be pinched off from the subarachnoid space and sequestered

Barkovich AJ, Vandermarck P, Edwards MS et al (1991) Congenital nasal masses: CT and MR imaging features in 16 cases. AJNR 12:105–116 Saettele, M., Alexander, A., Markovich, B. et al. Congenital midline nasofrontal masses. Pediatr Radiol 42, 1119–1125 (2012). https://doi.org/10.1007/s00247-012-2409-z](attachment:e74723e3-09b0-4740-85c7-4ee31a4aac87:image.png)

Embryopathogenesis of cerebral heterotopias. Schematic illustrates that cerebral heterotopias result from failed retraction of dural diverticula allowing aberrant neurological tissue to be pinched off from the subarachnoid space and sequestered

Anatomical classification:

Type	Frequency	Location
Extranasal	~60%	External nose (nasal bridge or glabella)
Intranasal	~30%	Within nasal cavity (turbinates or septum)
Mixed	~10%	Combined intra- and extranasal components

Clinical Features

Firm, non-compressible, non-pulsatile nasal or midline mass present at birth
No change with crying or straining (unlike encephalocele)
Nasal obstruction, respiratory distress (if intranasal)