Glial choristoma in the middle ear and mastoid bone: a case report

[Choristoma of the middle ear]

Choristoma is one of the varieties of congenital developmental anomalies, where one or another normal tissue of the body is located in an atypical place for itself. The short literary review of choristoma of middle ear is presented in article. A rare clinical cases of salivary gland choristoma of the middle ear (5-year-old girl with left-sided conductive hearing loss of III degree) and glial choristoma of the mastoid (19-year-old man with signs of chronic suppurative otitis media of the right ear) are described.

Rare Diseases of the Middle Ear and Lateral Skull Base

Otalgia, otorrhea and hearing loss are the most common ear-related symptoms that lead to the consultation of an otolaryngologist. Furthermore, balance disorders and affections of the cranial nerve function may play a role in the consultation. In large academic centres, but also in primary care, the identification of rare diseases of the middle ear and the lateral skull base is essential, as these diseases often require interdisciplinary approaches to establish the correct diagnosis and to initiate safe and adequate treatments. This review provides an overview of rare bone, neoplastic, haematological, autoimmunological and infectious disorders as well as malformations that may manifest in the middle ear and the lateral skull base. Knowledge of rare disorders is an essential factor ensuring the quality of patient care, in particular surgical procedures. Notably, in untypical, complicated, and prolonged disease courses, rare differential diagnoses need to be considered.

Neuroglial heterotopia of the middle ear: A case series and systematic literature review

Background

The differential diagnosis for mass forming lesions of the middle ear is broad. While uncommon, neuroglial heterotopias can occur in the middle ear and can be a source of diagnostic confusion for clinician, radiologist, and pathologist alike.

Methods

We identified three cases of neuroglial heterotopia of the middle ear in our institutional archives from 2000 to 2020 and performed extensive histological and immunohistochemical characterization of the three lesions. We conducted a systematic literature review to identify 27 cases published in the English literature between the years 1980 and 2020. Only cases with histological verification of neuroglial heterotopia specifically involving the middle ear were included. We compiled the clinical, radiological, and histopathological findings for all 30 cases.

Results

Patients most frequently presented with chronic otitis media (40%), hearing loss (40%), or prior history of ear surgery or trauma (13%). The median age at surgery was 49 years with a male predominance (M:F 2:1); however, a bimodal age distribution was noted with an earlier onset (11 years or younger) in a subset of patients. Immunohistochemical characterization showed mature neuronal and reactive glial populations with low Ki67 proliferation index and chronic inflammatory infiltrates. There was no neuronal dysplasia or glial atypia, consistent with benign, nonneoplastic, mature glioneuronal tissue.

Conclusion

Immunohistochemical characterization of these lesions and clinical follow-up confirms their benign natural history. Potential etiologies include developmental misplacement, trauma, and chronic inflammation/ reactive changes resulting in sequestered encephalocele.

Neuroglial Choristoma of the Middle Ear with Massive Tympanosclerosis: A Case Report and Literature Review

Neuroglialchoristoma is a rare cerebral heterotopia typically involving extracranial midline structures of the head and neck, including the nose, nasopharynx and oral cavity. It rarely involves non-midline structures, such as the middle ear, mastoid and orbit. We report the case of a 63-year-old woman with right-sided hearing loss and aural fullness who was diagnosed with neuroglialchoristoma of the middle ear and mastoid. To our knowledge, this is the first report on neuroglialchoristomawith massive tympanosclerosis. The presence of combination supported the inhalation theory of neuroglialchoristoma, given that tympanosclerosis is typically caused by Eustachian tube dysfunction.

Glial Choristoma in the Oral and Maxillofacial Region: A Clinicopathologic Study of 6 Cases

Context.—Glial choristoma is an uncommon developmental abnormality typically presenting at birth or in early childhood. The nasal region is most frequently affected. Palate, tongue, cheek, scalp, and orbit can also be affected but these occurrences are relatively rare.

Objective.—To report 6 cases of glial choristoma arising in the oral and maxillofacial region and to document the clinical and pathologic features of these lesions.

Design.—Histologic and immunocytochemical examinations were performed on 6 cases of glial choristoma. Biologic behavior, prognosis, and pathogenesis were discussed together with a review of the literature.

Result.—The patients included 5 boys and 1 girl. They all presented with the lesions at birth or soon after birth. Four lesions occurred on the dorsal side of the tongue, near the foramen caecum. One lesion was present in the infratemporal fossa and parapharyngeal space, and the other one was in the submandibular region. All patients received surgical excision, and follow-up data revealed no recurrence for a period of 10 months to 5 years after surgery. Histologically, the lesions showed mature glial cells intermixed with connective tissue. The glial tissue was strongly positive for glial fibrillary acidic protein and S100 but negative for neurofilament.

Conclusion.—Glial choristoma should be classified as a developmental malformation that occurs in many sites of the head and neck. In oral cavity, the tongue is the most frequently affected site. Although these lesions are rare, they should be included in the differential diagnosis of congenital masses in the oral and maxillofacial region.

Neuroglial choristoma of the middle ear

Neuroglial choristoma is a rare cerebral heterotopia which can involve various locations. Even if its occurrence is more frequent in midline structures, it can also be found in the non-midline structure such as, for example, even if only rarely, the middle ear. The described case is that of a 74-year-old male who had been operated on for a neuroglial choristoma located in the tympanic cavity and in the mastoid bone. High resolution computed tomography and intra-operative findings did not reveal any connection with the upper cerebral structures, thus excluding the hypothesis of an encephalocele. After careful histopathological examination, the aetiopathogenetic hypothesis are analysed. Only 8 similar cases have been reported in the literature.