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neuroglial heterotopia

Thursday 2 November 2006

brain heterotopia, cerebral heterotopia, heterotopic neural nodules, neural heterotopia, neuroglial ectopia, Neuroglial choristoma

Definition: Heterotopic neural nodules is a type of neuroectodermal malformation. They, are particularly dangerous because of the possibility of intracranial extension.

Neuroglial heterotopia, heterotopic brain tissue, or differentiated neural tissue outside the cranial vault is uncommon, and these anomalies most commonly occur in the nasal cavity.

Neuroglial ectopia has been defined as a mass composed of differentiated neuroectodermal tissue isolated from the spinal canal or cranial cavity and remains rare.

The anatomopathological examination showed a solid mass with nests of neural tissue, with some neurons embedded in poorly encapsulated fibrovascular stroma, without mitotic areas, and with presence of functioning choroid plexus.

Neuroglial ectopia needs to be considered in diagnosing airway obstruction among newborns. Surgical treatment is the best choice and should be performed on clinically stable patients.

This lesion has to be considered in the differential diagnosis among newborn infants with classical symptoms of respiratory distress, neck mass and feeding difficulties.

Pure cystic neck heterotopic brain tissue lesions are very uncommon, and a preoperative diagnosis of this lesion is difficult.

Brain heterotopia is a rare, benign condition that should be considered in the differential diagnosis of the neonatal head and neck mass.

Neuroglial heterotopia, heterotopic brain tissue, or differentiated neural tissue outside the cranial vault is uncommon, and these anomalies most commonly occur in the nasal cavity.

In rare instances, neuroglial heterotopia in the neck has been reported.

The most common location of heterotopic brain tissue is in the nasal region. However, heterotopic brain tissue has also less commonly been reported to occur in other sites, such as the pharynx, lung, orbits, palate, tongue, cheek, lip, and neck.

Heterotopic neuroglial tissue (HNT) was first described by Reid in 1852. Composed of differentiated neuroectodermal tissue, these lesions represent developmental heterotopia of neuroglial tissue rather than true neoplasms.

Unlike meningoencephaloceles, brain heterotopias lack connection with the subarachnoid space.

Patients are usually seen initially in the newborn period with airway obstruction, feeding difficulty, or a neck mass.

The most common location of HNT is the nasal cavity, where it is traditionally but erroneously termed ’nasal glioma’.

Less commonly, brain heterotopias have been reported in the scalp, tongue, pharynx, palate, orbit, and neck.

The majority of patients with HNT are products of uncomplicated pregnancies.

This anomaly seems to have a left side and female predominance in previously reported cases.

Other associated developmental anomalies have been reported, such as cleft palate, Pierre-Robin syndrome, and congenital heart disease.

The pathogenesis of heterotopic neuroglial tissue is unclear. Several mechanisms have been proposed. CT and MRI scans are complementary studies necessary in pre-operative planning to determine the extent and location of the mass and to exclude intra-cranial connection.

Surgical excision is the treatment of choice, although the time it should be performed is controversial.

Synopsis

- heterotopic leptomeningeal tissue
- glial tissue
- heterotopic brain tissue
- cystic pattern
- pure cystic heterotopic brain tissue
- neuroglial heterotopia
- glial cells in a neurofibrillary matrix
- cleft lined by ependymal-like columnar cells and surrounded by meninges
- no malignancy

Localization

- face
- submandibular neuroglial heterotopia
- parapharyngeal neuroglial heterotopia
- skull base neuroglial heterotopia
- scalp neuroglial heterotopia(#15692339#)
- lung neuroglial heterotopia(#7076204#)
- abdominal surface of the diaphragm neuroglial heterotopia (#7076204#)
- middle ear (#17608139#)

Association

- anencephaly (#7076204#)

Management

The treatment for heterotopic brain tissue is complete surgical excision.

Surgical intervention is necessary in patients with heterotopic parapharyngeal neuroglial tissue that causes airway distress, dysphagia, or failure to thrive.

The timing of surgery is controversial. Proponents of delayed resection believe that resection might be safer in the older child, in whom vital neurovascular structures are more easily salvageable and blood volume is greater.

Recurrence as a result of incomplete excision has been described.

Although focal areas of immature cells have been reported, these masses lack invasive patterns and are not true neoplasms.

Rigorous post-operative care includes attention to nutritional status and speech and swallowing therapy.

Open references

- Respiratory difficulty caused by an ectopic brain tissue mass in the neck of a two-month-old baby: a case report. Aboud MJ. J Med Case Reports. 2011 Jun 8;5(1):220. PMID: #21649939# (Free)

- Extensive parapharyngeal and skull base neuroglial ectopia; a challenge for differential diagnosis and treatment: case report. Melo GM, Gonçalves Gdo N, Souza RA, Sguillar DA. Sao Paulo Med J. 2010;128(5):302-5. PMID: #21181072# [Free]

- Neuroglial choristoma of the middle ear. Farneti P, Balbi M, Foschini MP. Acta Otorhinolaryngol Ital. 2007 Apr;27(2):94-7. PMID: #17608139# [Free]

- Parapharyngeal neuroglial heterotopia presenting as a growing single locular cyst: MR imaging findings. Chen CY, Huang JH, Choi WM, Chen CL, Chan WP. AJNR Am J Neuroradiol. 2005 Jan;26(1):96-9. PMID: #15661709# [Free]

References

- Azumi N, Matsuno T, Tateyama M, Inoue K. So-called nasal glioma. Acta Pathol Jpn. 1984;34:215–220.

- Hendrikson M, Faye-Petersen O, Johnson DG. Cystic and solid heterotopic brain in the face and neck: a review and report of an unusual case. J Pediatr Surg. 1990;25:766–768.

- Broniatowski M, Witt WJ, Shah AC, Galloway PG, Abramowsky CR. Glial tissue in the parapharyngeal space. Arch Otolaryngol. 1981;107:638–641.

- Forte V, Friedberg J, Thorner P, Park A. Heterotopic brain in the parapharyngeal space. Int J Pediatr Otorhinolaryngol. 1996;37:253–260. doi: 10.1016/0165-5876(96)01401-2.

- Behar PM, Muller S, Gerber ME, Todd NM. Heterotopic neurotopic neuroglial tissue causing airway obstruction in the newborn. Arch Otolaryngol Head Neck Surg. 2001;127:997–1002.

- Chen CY, Huang JH. Parapharyngeal neuroglial heterotopia presenting as a growing single locular cyst: MR imaging findings. Am J Neuroradiol. 2005;26:96–99.

- Ducic Y. Nasal gliomas. J Otolaryngol. 1999;28:285–287.

- Uemura T, Yoshikawa A, Onizuka T, Hayashi T. Heterotopic nasopharyngeal brain tissue associated with cleft palate. Cleft Palate Craniofac J. 1999;36:248–251.

- Hendrickson M, Faye-Petersen O, Johnson DG. Cystic and solid heterotopic brain in the face and neck: a review and report of an unusual case. J Pediatr Surg. 1990;25:766–768.

- Robbins SH, Tomaszewski MM, Garcia VF, Eggli KD, d’Avis JC. Heterotopic brain presenting as a cystic neck mass with mandibular deformity. Pediatr Pathol. 1985;4:341–349.

- Chen CY, Huang JH, Choi WM, Chen CL, Chan WP. Parapharyngeal neurological heterotopia presenting as a growing single locular cyst. AJNR Am J Neuroradiol. 2005;26:96–99.

- Chan CY, Lim KE. Cystic heterotopic brain tissue presenting as a unilateral neck mass. Tzu Chi Med J. 2006;18:217–219.

- Kallman JE, Loevner LA, Yousem DM, Chalian AA, Lanza DC, Jin L, Hayden RE. Heterotopic brain in the pterygopalatine fossa. AJNR Am J Neuroradiol. 1997;18:176–179.

- Madjidi A, Couley G. Heterotopic neuroglial tissue of the face. Oral Surg Oral Med Oral Pathol. 1993;76:284–288.

- Seibert RW, Seibert JJ, Jimenez JF, Angtuaco EJ. Nasopharyngeal brain heterotopia: a cause of upper airway obstruction in infancy. Laryngoscope. 1984;94:818–819.

- Patterson K, Kapur S, Chandra R. Nasal glioma and related brain heterotopias: a pathologist’s perspective. Pediatr Pathol. 1986;5:353–361.

- Bossen EH, Hudson WR. Oligodendroglioma arising in heterotopic brain tissue of the soft palate and nasopharynx. Am J Surg Pathol. 1987;11:571–574.

- Lee SC, Henry MM, Gonzalez-Crussi F. Simultaneous occurrence of melanotic neuroectodermal tumor and brain heterotopia in the oropharynx. Cancer. 1967;38:249–253.

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