A Clinicopathological Study of 15 Patients With Neuroglial Heterotopias and Encephaloceles of the Middle Ear and Mastoid Region

Abstract

Operative findings revealed that two lesions had definite CNS connections and two were unrelated to the CNS; this relation could not be determined in the remaining cases. Seven of 10 patients for whom clinical information was available had a history of chronic otitis media or mastoiditis or both; four of these seven patients also had a history of previous trauma or surgery. Three patients, including both patients whose lesions had no demonstrable CNS attachment, had no predisposing factors. Conclusions: Most neuroglial heterotopias of the middle ear are probably acquired encephaloceles. These lesions occur in older patients than do their midline counterparts. Determination of the relation of these lesions to adjacent CNS structures must be done radiographically or using operative findings, because histology alone cannot be reliably used to render an accurate diagnosis.

Glial heterotopia in head and neck, single center experience of 5 cases

“…3 Unlike their midline counterparts, most middle ear region neuroglial heterotopias are diagnosed in adult patients. 1 Similar to the literature, middle ear glial heterotopia was diagnosed in an adult patient.…”

“…Lesions involving non-midline structures, and specifically, the middle ear region, are often not recognized and may be misdiagnosed as neoplasms such as teratomas (when adjacent non-neural tissues are present), gliomas, meningiomas, or schwannomas. 1 The pathogenesis of these lesions is uncertain. various hypotheses have been postulated.…”

“…4 One commonly accepted theory is that heterotopic neural tissue is a variant of encephalocele in which the central nervous system connection has been absorbed or become vestigial. 1,5 These lesions may be classified based on their location and possible pathogenic mechanisms as follows: a) intraparenchymal CNS lesions; b) dural and lepto-meningeal lesions; c) intracranial extra-cerebral lesions; d) distal lesions thought to result from a previous pregnancy; e) midline "nasal gliomas," thought to originate as encephaloceles; and f) non-midline lesions of the head and neck. 1 Nasal Glial Heterotopias (NGH) are congenital tumours of the midline frontonasal space arising from a normal neuroectodermal tissue entrapped during the closure of the anterior neuropore.…”

“…Histologically, these lesions are composed of neurons and glial tissue, with some associated chronic inflammation and gliosis.Lesions involving the middle ear region, are often not recognized and may be misdiagnosed as neoplasms such as teratomas (when adjacent non-neural tissues are present), gliomas, meningiomas, or schwannomas. 1 The differential diagnosis of Glial Heterotopia includes encephalocoeles, hemangiomas, dermoid or epidermoid cysts, as well as malignant tumors such as rhabdomyosarcoma. 12 Radiographic assessment of Nasopharyngeal glial heterotopia is best performed using CT complemented by MRI.…”

“…Initial description of glial heterotopias over the dorsal surface of the cervical spinal cord was in 1907. 1 The nose and the naso-pharynx are the most common sites of location. 2 Even if its occurrence is more frequent in midline structures, it can also be found in the non-midline structure rarely such as the middle ear.…”