Nasal Glioma

Nasal cerebral heterotopia: the so-called nasal glioma or sequestered encephalocele and its variants

Twenty two nasal cerebral heterotopias were compared with 11 nasal encephaloceles. No histological feature was found that would allow a communication with the brain to be confidently identified or excluded. Even laminated cerebral cortex with neurones and ependymal canals, suggestive of encephalocele, were found in heterotopias. Distinction required radiological and surgical evidence. However, CT scan could be misleading, in one infant suggesting a cribriform plate defect when none was found at craniotomy. Three children had multiple extracranial glial lesions, two with both heterotopia and encephalocele in the same patient. In a few older children it was extremely difficult to identify brain tissue because of marked replacement by fibrous tissue (up to 95%), leading to one misdiagnosis as fibroma, and considerable fibrosis occurred also in five of six recurrences and in a longstanding small encephalocele. In two heterotopias, cellularity in places approached that of low-grade neoplastic glioma. One nasopharyngeal heterotopia contained multiple mesenchymal tissues suggestive of teratoma. Two midline nasopharyngeal encephaloceles showed adjacent epithelium, possibly vestiges of Rathke's pouch.

Ectopic brain in the orbit

We report a case of ectopic brain tissue in the orbit associated with a bony defect of the orbit and the presence of skeletal muscle. Previous reports of orbital ectopic brain and related lesions in the orbit and at other sites are reviewed.

Intraorbital and intracranial glial hamartoma: case report

A case is reported of a glial hamartoma located in the orbital fossa, with an extradural extension to the middle fossa. This location of a glial hamartoma has not previously been reported.

Nasal glioma

Six cases of nasal gliomas, which are rare ectopic rests of neural tissue found at the root of the nose, are presented. It is important to distinguish nasal tumors from basofrontal encephaloceles to avoid inadvertent exposure of the brain during the surgical removal of mass lesions. Because of their related embryologic origins, the distinction between nasal gliomas and basofrontal encephaloceles may not be clear clinically. Nasal gliomas may be treated by several surgical specialties, and only a proper awareness of their relatonship to encephaloceles can assure the selection of a flexible and adequate surgical approach. This paper emphasizes the salient clinical characteristics of nasal gliomas, their clinical distinction form and embryologic relationship to encephaloceles, and the options for treatment.