Nasal gliomas. A review and report of two cases

Abstract

Nasal gliomas are rare, benign, congenital tumors which are thought to be the result of an error in embryonic development. They have the same type of origin as encephaloceles but the meningeal continuity has closed, resulting in “vestigial encephaloceles.” They are found in both sexes with a slight male predominance. They are 60% extranasal and 30% intranasal. The rest are mainly combined defects. In 20% of the cases there is a mainly fibrous connection to the intracranial space. Clinically they are firm, noncompressible, nonpulsatile, gray or purple tumors obstructing the nasal cavity intranasally and causing nasal deformity extranasally. Histologically they are composed of astrocytic neuroglial cells interlaced with fibrous and vascular connective tissue covered by skin or nasal respiratory mucosa. Surgical extirpation of the extracranial portion of the tumor is the treatment of choice. If in differential diagnosis there is a firm suspicion of encephalocele, neurosurgical exploration of the anterior cranial fossa must be done first. Any preoperative biopsies or any partial nasal interventions must be abandoned. Here we review the 69 cases since the tabulation of Walker and Resler in 1963, and two cases of our own are added.

Adult nasal glioma presenting with visual loss

“…5 The tumour has a male-to-female ratio of 3:2, and there is no recognised familial tendency or association with other developmental anomalies. 6,7 It is widely accepted that these lesions result from aberrations in normal embryonic development. 4 In particular, nasal gliomas are thought to represent basal or sincipital encephalocoeles that have lost their intracranial meningeal connection.…”

“…Nasal gliomas have no meningeal envelope and are covered only by skin or nasal respiratory mucosa. 7 Secondary changes of fibrogliosis or gemistiocytic alteration of glial cells are often seen, 12 probably due to compression and infarction of neural tissue. This can make nasal gliomas histologically indistinguishable from encephalocoeles; in this case, differentiation is possible only based on radiological or surgical evidence.…”

Ectopic Brain Tissue in a Neonate

“…This entity most commonly occurs in the nasal region and is often referred to as a nasal glioma. Fibrous connections to the intracranial space are seen in 20–25% of these lesions [2, 3]. Non-nasal locations for misplaced central nervous system tissue are rare.…”

Adult nasal gliomas

“…[6][7][8][9] Ten to 15 per cent of gliomas have a dural connection, with a fibrous stalk extending towards a defect in the skull base. [10][11][12][13] The likelihood of a dural connection is two to three times higher for intranasal gliomas as compared with their external counterparts.…”