A clinicopathological study of 15 patients with neuroglial heterotopias and encephaloceles of the middle ear and mastoid region

Unveiling Nasal Glial Heterotopia: A Pathological Perspective

The uncommon, non-hereditary congenital abnormalities known as nasal glial heterotopias (NGH) are composed of heterotopic neuroglial tissue. Typically, NGH manifests in infancy, but occasionally it can also be seen in older children and adults. To rule out intracranial extension, magnetic resonance imaging (MRI) and computed tomography (CT) scans should be performed. Numerous cases have been documented where NGH was mistakenly identified as encephaloceles, teratomas, dermoid cysts, capillary haemangiomas, and even desmoids. A proper clinical, sonological, and even CT and MRI evaluation can lead to a near-final diagnosis; nonetheless, surgical excision and histological confirmation are the gold standards. We report a rare case of a firm, subcutaneous, non-tender, non-reducible midline 2 x 2 x 1 cm swelling with bluish-red skin near the root of the nose that was not affected by posture or pressure. Encephalocele, NGH, and dermoid were the differential diagnoses made based on the oedema found on CT and MRI scans. Histopathology provided a conclusive NGH diagnosis. The instance illustrates the significance of histology as the gold standard for NGH diagnosis.

Glial Heterotopia of the Middle Ear: First Case in Indian Literature

A 66-years-old female presented with impaired hearing of two-year duration and a recent ear discharge. High-resolution computed tomography and intra-operative findings showed a mass lesion in the right middle ear cavity that was unconnected with the brain. A histopathological diagnosis of glial heterotopia was made and an etiopathogenic hypothesis was analysed.

Ovarian Neuroglial Choristoma in a Bitch

Neuroglial choristomas are rare malformations consisting of heterotopic mature neural tissue at a site isolated from the brain or spinal cord. In human medicine, neuroglial choristomas are predominantly reported in the head and in the neck, except for one recent case reported in a foot of a child. In domestic animals, neuroglial choristomas are exceedingly rare, reported only in the retina of a dog, in the pharynx and in the skin of two kittens, and within the oropharynx of a harbor seal. A three-year-old intact female Jack Russell Terrier presented for elective ovariectomy exhibited a cystic lesion 2 cm in diameter expanding in the right ovary. Histological examination of the lesion revealed a mass composed of well-organized neuroglial tissue. Immunohistochemistry with primary antibodies against GFAP, NSE, and IBA-1 confirmed the neuroglial origin of the mass. At the time of this writing, 7 years after ovariectomy, the dog was clinically normal. Together with a recent case described in the foot of a child, this case confirms that neuroglial choristoma may also be found far from the skull or spine, supporting the hypothesis that they may arise from an early embryological migration defect.

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.

A Rare Case Report of Encephalocele with Numerous Ependymal Components: A Potential Diagnostic Pitfall

Different cellular constituents of the central nervous system occurring in encephaloceles or neuroglial heterotopias (NGHs) have been reported, but the ependymal morphology has rarely been described in the previous literature, let alone the related histological images. To determine the ependymal morphology in encephaloceles or NGHs, we report a rare case of encephalocele with numerous ependymal components. Radiological examination showed that a 6.2 × 3.1 cm nasal dorsum mass-forming encephalocele in a 24-year-old woman, who had an intracranial connection through a frontal bone defect. This patient underwent a resection of the encephalocele under nasal endoscopy and a reconstruction of the cranial base. The patient had a good prognosis with no postoperative complications during follow-up. Microscopically, the ependymal components entrapped in a collagenized background showed numerous slit-like spaces lined by columnar cells with abundant palely eosinophilic cytoplasm and apical surface microvilli. With immunohistochemistry, in addition to the expression of EMA along with the slit-like spaces, GFAP and S100 were diffusely expressed in the slit-like spaces. In conclusion, the ependymal component in either encephaloceles or NGHs may present slit-like spaces arranged in an anastomosing pattern. The unusual morphology of ependyma continues to be underrecognized by pathologists and is easily misdiagnosed; therefore, an awareness of the morphological change in ependyma is necessary.

Ocular Neural Heterotopia in a Moroccan Uromastyx (Uromastyx acanthinurus nigriventris)

A juvenile female Moroccan uromastyx (Uromastyx acanthinurus nigriventris) that died unexpectedly was necropsied. Necropsy examination revealed minimal intracoelomic fat, small numbers of intestinal nematodes and intraocular masses within the vitreous chamber of both eyes. One of the intraocular masses was focally contiguous with the optic nerve and composed of neuroparenchyma with rare glial cells, consistent with a diagnosis of neural heterotopia. This condition is considered a neuroectodermal malformation, readily recognized in human medicine but rarely reported in animals. To the authors' knowledge, this is the first case of intraocular neural heterotopia reported in a reptile.

Congenital neuroglial choristoma of the foot

Neuroglial choristomas are rare malformations of heterotopic neural tissue that have been previously reported predominantly in the head and neck. Competing theories of embryogenesis propose their origin as encephaloceles that have undergone resorption of their cranial connection or displaced neuroectodermal cells which have undergone ectopic proliferation. Most cases occur in midline or para-midline structures. There have been no prior published cases of a neuroglial choristoma in the extremities. We present a case of a 13-month-old otherwise healthy child who presented to our institution with a slowly growing foot mass who was found to have a neuroglial choristoma. This case suggests an early embryological migration defect as the etiology and offers a unique differential consideration for a benign extremity mass.

Ear and Temporal Bone Pathology: Neural, Sclerosing and Myofibroblastic Lesions

Neural, sclerosing, and myofibroblastic lesions of the ear and temporal bone present diagnostic challenges for both clinicians and pathologists due to significant overlap in their clinical presentations, histologic appearances, and immunohistochemical profiles. While some of these lesions, such as schwannomas, are relatively common, others are rendered even more difficult because they are encountered very rarely in routine surgical pathology practice. This review is intended to provide an update on the pathology of some of the most commonly encountered primary diagnostic entities for the ear and temporal bone, and includes the following neural lesions: schwannoma, meningioma, and encephalocele/meningocele. Sclerosing lesions that will be discussed include spindle cell and sclerosing rhabdomyosarcoma, sclerosing epithelioid fibrosarcoma, and sclerosing paraganglioma. Finally, myofibroblastic lesions that will be reviewed are nodular fasciitis, IgG4-related disease, and solitary fibrous tumor. For each of these lesions, the differential diagnosis and useful ancillary tests will be discussed in the context of a broad range of additional primary and secondary lesions.

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.

Case series of congenital heterotopic neuroglial tissue in the parapharyngeal space

Cases of congenital heterotopic tissue presenting in the head and neck are frequent in the pediatric otolaryngology literature. Heterotopic glioneuronal tissue is rare and fewer than 20 cases of heterotopic glioneuronal tissue in the parapharyngeal space have been reported. We present two cases of infant children who were seen at the Children's Hospital of Pittsburgh in 2013 with glioneuronal heterotopic masses in the parapharyngeal space.

Selective pathologies of the head and neck in children: a developmental perspective

The range of pathology seen in the head and neck region is truly amazing and to a large extent probably mirrors the complex signaling pathways and careful orchestration of events that occurs between the primordial germ layers during the development of this region. As is true in general for the entire discipline of pediatric pathology, the head and neck pathology within this age group is as diverse and different as its adult counterpart. Cases that come across the pediatric head and neck surgical pathology bench are more heavily weighted toward developmental and congenital lesions such as branchial cleft anomalies, thyroglossal duct cysts, ectopias, heterotopias, choristomas, and primitive tumors. Many congenital "benign" lesions can cause significant morbidity and even mortality if they compress the airway or other vital structures. Exciting investigations into the molecular embryology of craniofacial development have begun to shed light on the pathogenesis of craniofacial developmental lesions and syndromes. Much more investigation is needed, however, to intertwine aberrations in the molecular ontogeny and development of the head and neck regions to the represented pathology. This review will integrate traditional morphologic embryology with some of the recent advances in the molecular pathways of head and neck development followed by a discussion of a variety of developmental lesions finishing with tumors presumed to be derived from pluripotent/progenitor cells and tumors that show anomalous or aborted development.

Parapharyngeal neuroglial heterotopia in Pierre Robin sequence: MR imaging findings

Heterotopic neuroglial tissue is a rare lesion, occurring more frequently in the nasal cavities. Other rare locations are the orbit, the scalp, the palate, the pharynx, the parapharyngeal space and the lungs. They are usually detected occasionally because they are often asymptomatic, but sometimes they might present with dyspnoea, feeding difficulty, snorting and nasal flaring. Respiratory symptoms occur when heterotopic neuroglial tissue is located in the parapharyngeal space. We report a case of an infant affected by Pierre Robin sequence (PRS) who was admitted to our Institution for a worsening respiratory distress that was not explainable only by PRS.

Brain in the middle ear or nasal cavity: heterotopia or encephalocele?

Brain in the middle ear or nasal cavity: heterotopia or encephalocele? The answer to this question is greatly influenced by clinical information. Sometimes, however, this information is insufficient and the pathologist's opinion may influence patient management. It seems that most pathologists tend to get the answer wrong. This article will enable you to arrive at the correct answer.

Nasal glial heterotopia: a clinicopathologic and immunophenotypic analysis of 10 cases with a review of the literature

Nasal glial heterotopia (also known as "nasal glioma"), is a rare developmental abnormality seen in a wide age group but typically presenting at birth or in early childhood. Failure to recognize the entity is the principle difficulty in diagnosis. Ten cases of nasal glial heterotopic diagnosed between 1970 and 2000 were identified. Histologic and immunohistochemical features were evaluated and patient follow-up was obtained. The patients included five females and five males with a mean age at presentation of 8.6 years (range, birth to 44 years). Most patients presented clinically with a polypoid mass in the nasal cavity, although two patients had a mass on the nasal bridge. Symptoms were present for an average of 2 to 3 months. A connection to the central nervous system was identified in one case. Masses ranged in size from 1 to 7 cm in greatest dimension (mean, 2.4 cm). Histologically, the masses were composed of astrocytes (including gemistocytic type) and neuroglial fibers intermixed with a fibrovascular connective tissue stroma. Neurons and ependymal cells were noted in two cases. Focal calcifications and inflammatory cells were identified occasionally. Masson trichrome stains the collagen intensely blue, while the neural population stains magenta. Immunohistochemical reactivity with glial fibrillary acidic protein and S-100 protein will help to confirm the histologic diagnosis, while collagen type IV and laminin can highlight the reactive fibrosis. All cases were managed by surgery. All patients were alive without complications at last follow-up (mean, 26.8 years), except for the single fetus included in the study. Nasal glial heterotopia typically involves the nasal cavity and usually presents perinatally, although three patients presented in adulthood. The subtle glial component on routine microscopy can be accentuated with a trichrome stain or by immunoreactivity with glial fibrillary acidic protein and S-100 protein. Imaging studies must be performed before surgery to exclude an encephalocele, which requires different surgery. Complete surgical excision of nasal glial heterotopias is curative.

Mature teratoma arising from the middle cranial fossa

A 25-year-old man presented with a sudden spurt in size of a bony swelling around the external ear, which was present since birth. This was associated with a painful swelling of the right half of the face and pain, redness, and decreased vision in the right eye. Neurologic examination showed decreased visual acuity in the right eye and paresis of the fifth, seventh, and eighth cranial nerves. Neuroimaging showed an extra-axial, partly cystic tumor of mixed density, located entirely within the middle cranial fossa scalloping the temporal bone and extending into the right infratemporal fossa and the right middle ear and impinging on the ipsilateral cavernous sinus. The right temporal lobe was elevated and compressed. Histopathologic examination confirmed a mature teratoma.

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

Heterotopic brain tissue usually involves extracranial midline structures of the head and neck such as nose, nasopharynx, and oral cavity. Its occurrence in the non-midline structures, including middle ear, is rare. We described a 50-yr-old-man with heterotopic glial tissue in the middle ear and mastoid bone. The patient presented with progressive hearing loss for 8 yr. There was no history of congenital anomalies, trauma, or ear surgery. Computed tomography revealed a mass-like lesion with soft tissue density occupying the middle ear cavity and mastoid antrum. At the operation, a gray-white fibrotic mass was detected in the epitympanic area. Mesotympanum and ossicles were intact. The patient underwent left simple mastoidectomy with type I tympanoplasty. During operation, definite cranial bone defect or cerebrospinal fluid leakage was not found. Histologically, the lesion was composed of exclusively mature, disorganized glial tissue with fibrovascular elements in a rather loose fibrillary background. Glial tissue showed diffuse positive reaction for glial fibrillar acidic protein and S100 protein on immunohistochemical study.

Primary ear and temporal bone meningiomas: a clinicopathologic study of 36 cases with a review of the literature

"Primary" ear and temporal bone meningiomas are tumors that are frequently misdiagnosed and unrecognized, resulting in inappropriate clinical management. To date, a large clinicopathologic study of meningiomas in this anatomic site has not been reported. Thirty-six cases of ear and temporal bone meningiomas diagnosed between 1970 and 1996 were retrieved from our files. Histologic features were reviewed, immunohistochemical analysis was performed (n = 19), and patient follow-up was obtained (n = 35). The patients included 24 females and 12 males, aged 10-80 years (mean, 49.6 years), with female patients presenting at an older age (mean, 52.0 years) than male patients (mean, 44.8 years). Patients presented clinically with hearing changes (n = 20), otitis (n = 7), pain (n = 5), and/or dizziness/vertigo (n = 3). Symptoms were present for an average of 24.6 months. The tumors affected the middle ear (n = 25), external auditory canal (n = 4), or a combination of temporal bone and middle ear (n = 7). The tumors ranged in size from 0.5 to 4.5 cm in greatest dimension (mean, 1.2 cm). Radiographic studies demonstrated a central nervous system connection in 2 patients. Histologically, the tumors demonstrated features similar to those of intracranial meningiomas, including meningothelial (n = 33), psammomatous (n = 2), and atypical (n = 1). An associated cholesteatoma was identified in 9 cases. Immunohistochemical studies confirmed the diagnosis of meningioma with positive reactions for epithelial membrane antigen (79%) and vimentin (100%). The differential diagnosis includes paraganglioma, schwannoma, carcinoma, melanoma, and middle ear adenoma. Surgical excision was used in all patients. Ten patients developed a recurrence from 5 months to 2 years later. Five patients died with recurrent disease (mean, 3.5 years), and the remaining 30 patients were alive (n = 25, mean: 19.0 years) or had died (n = 5, mean: 9.5 years) of unrelated causes without evidence of disease. We conclude that extracranial ear and temporal bone meningiomas are rare tumors histologically similar to their intracranial counterparts. They behave as slow-growing neoplasms with a good overall prognosis (raw 5-y survival, 83%). Extent of surgical excision is probably the most important factor in determining outlook because recurrences develop in 28% of cases.