Nasal glial heterotopia

Nasal glial heterotopia, also commonly known as nasal glioma, is a rare congenital developmental malformation consisting of ectopic brain tissue (glial tissue) located in or around the nose. Despite the term 'glioma,' this condition is not a true neoplasm but rather a developmental anomaly resulting from sequestration of glial tissue outside the cranial cavity during embryonic development. It is thought to represent a form of encephalocele that has lost its intracranial connection, though in some cases a fibrous stalk connecting to the dura mater may persist. Nasal glial heterotopia typically presents at birth or in early infancy as a firm, non-compressible mass located either externally on the nasal bridge (extranasal, approximately 60% of cases), within the nasal cavity (intranasal, approximately 30%), or in a combined location (approximately 10%). External lesions appear as smooth, firm, skin-covered masses near the root of the nose, sometimes with a bluish discoloration. Intranasal lesions may cause nasal obstruction, difficulty breathing (especially in neonates who are obligate nasal breathers), and feeding difficulties. The mass does not transilluminate and does not increase in size with crying or straining (Furstenberg test negative), which helps distinguish it from an encephalocele. Rarely, the condition may be associated with other craniofacial anomalies. Diagnosis is established through clinical examination, imaging studies (CT and MRI are essential to evaluate any intracranial connection and to differentiate from encephalocele), and histopathological confirmation showing mature glial tissue with astrocytes embedded in a fibrous connective tissue matrix. Treatment is primarily surgical excision, which is both diagnostic and curative. Complete surgical removal is important to prevent recurrence, which occurs in approximately 10% of incompletely excised cases. Prognosis after complete excision is excellent, with no risk of malignant transformation. Preoperative imaging is critical to rule out intracranial communication before any surgical intervention is attempted.

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