Pediatric primary pilocytic astrocytoma of the cerebellopontine angle: a case report

An integrative survival analysis and a systematic review of the cerebellopontine angle glioblastomas

Glioblastomas presenting topographically at the cerebellopontine angle (CPA) are exceedingly rare. Given the specific anatomical considerations and their rarity, overall survival (OS) and management are not discussed in detail. The authors performed an integrative survival analysis of CPA glioblastomas. A literature search of PubMed, Scopus, and Web of Science databases was performed per PRISMA guidelines. Patient data including demographics, clinical features, neuroimaging, management, follow-up, and OS were extracted. The mean age was 39 ± 26.2 years. The mean OS was 8.9 months. Kaplan-Meier log-rank test and univariate Cox proportional-hazards model identified hydrocephalus (log-rank, p = 0.034; HR 0.34; 95% CI 0.12-0.94; p = 0.038), chemotherapy (log-rank, p < 0.005; HR 5.66; 95% CI 1.53-20.88; p = 0.009), and radiotherapy (log-rank, p < 0.0001; HR 12.01; 95% CI 3.44-41.89; p < 0.001) as factors influencing OS. Hydrocephalus (HR 3.57; 95% CI 1.07-11.1; p = 0.038) and no adjuvant radiotherapy (HR 0.12; 95% CI 0.02-0.59; p < 0.01) remained prognostic on multivariable analysis with fourfold and twofold higher risk for the time-related onset of death, respectively. This should be considered when assessing the risk-to-benefit ratio for patients undergoing surgery for CPA glioblastoma.

Glioblastoma multiforme at internal auditory canal

Background

Glioblastomas are the most common adult primary brain tumor present supratentorially. The presence of true extra-axial GBM infratentorially, especially in the internal auditory canal, is extremely rare with only three cases reported previously in the literature. We report the fourth case of primary internal auditory canal/cerebellopontine angle (CPA) glioblastoma which initially mimicked vestibular schwannoma on the basis of its location and presentation.

Case Description

A 65-year-old male presented with headache, vertigo, and progressive right ear deafness for 5 months. His preoperative magnetic resonance imaging findings were consistent with vestibular schwannoma. Maximum safe resection (near total) was done. The final histopathology report showed glioblastoma multiforme.

Conclusion

As per our knowledge, this is the fourth reported case of an extra-axial VIII cranial nerve glioblastoma located in internal auditory canal. Hence, despite being very rare, they should be considered as a differential in tumors at CPA.

Pilocytic Astrocytoma of the Cerebellopontine Angle with cerebrospinal fluid Spread in an Adult: A Case Report

Introduction Pilocytic astrocytoma of the cerebellopontine angle (CPA) is uncommon, and its spread to the cerebrospinal fluid (CSF) at the time of diagnosis has not been reported in the literature.

Case Presentation We report the case of a 33-year-old man with multifocal pilocytic astrocytoma diagnosed by magnetic resonance imaging (MRI) and confirmed by histopathological examination, and present the radiological and histopathological findings.

Conclusion In the case herein reported, we observed spread of the pilocytic astrocytoma of the CPA to the CSF at the initial diagnosis, and early detection by MRI is very important regarding the treatment modality and prognosis.

Pilocytic astrocytoma of the cerebellopontine angle: a rare case

Background

Pilocytic astrocytomas are the most common primary brain tumors in children. Most of the lesions occur in or near the midline. They are rare in extra-axial locations.

Case presentation

We report a 23-year-old lady who was found to have progressive right-sided sensorineural hearing loss and features of raised intracranial pressure due to a pilocytic astrocytoma of the right cerebellopontine angle. After an extensive Medline search, we could find only three cases of primary extra-axial pilocytic astrocytoma of the cerebellopontine angle (CPA) reported till now.

Conclusion

Even a rare occurrence, primary pilocytic astrocytoma, and in general gliomas, should be kept in mind in the differential diagnosis of CPA lesions.

Primary pilocytic astrocytoma of the cerebellopontine angle in pediatric patient with neurofibromatosis type 1: a case report

Background

Cerebellopontine angle tumor (CPA) in pediatrics is rare as compared to adults. We describe a case of pediatric pilocytic astrocytoma presented as a right CPA mass with a concurrent clinical diagnosis of neurofibromatosis type 1 (NF1).

Case presentation

A 14-year-old boy with a newly diagnosed hypertension presented with a short history of headache and blurring vision. Neurological examination revealed bilateral papilloedema, partial right third nerve palsy and mild sensorineuronal hearing deficits. Skin examination identified multiple café au lait spots with cutaneous neurofibromas. Preoperative neuroimaging suggested the diagnosis of an extraaxial CPA mass consistent with meningioma, with obstructive hydrocephalus. A left ventriculoperitoneal shunt was inserted and the child was subjected for a suboccipital retrosigmoid approach for tumor resection. The histopathological features, however, were typical for pilocytic astrocytoma.

Conclusions

A careful evaluation of the clinical presentation and radiological images of CPA lesions is necessary prior to surgical embarkment. To the best of our knowledge, this case is the first report of pilocytic astrocytoma in the CPA in pediatric with NF1.

Surgical management of primary and secondary pilocytic astrocytoma of the cerebellopontine angle (in adults and children) and review of the literature

Glial tumors in the cerebellopontine angle (CPA) are uncommon and comprise less than 1% of CPA tumors. We present four cases of pilocytic astrocytoma of the CPA (PA-CPA) that were treated in our department. Patients who received surgical treatment for PA-CPA from January 2004 to December 2019 were identified by a computer search of their files from the Department of Neurosurgery, Tübingen. Patients were evaluated for initial symptoms, pre- and postoperative facial nerve function and cochlear function, complications, and recurrence rate by reviewing surgical reports, patient documents, neuroradiological data, and follow-up data. We identified four patients with PA-CPA out of about 1500 CPA lesions (~ 0.2%), which were surgically treated in our department in the last 16 years. Of the four patients, three were male, and one was a female patient. Two were adults, and two were children (mean age 35 years). A gross total resection was achieved in three cases, and a subtotal resection was attained in one case. Two patients experienced a moderate facial palsy immediately after surgery (House–Brackmann grade III). In all cases, the facial function was intact or good (House–Brackmann grades I–II) at the long-term follow-up (mean follow-up 4.5 years). No mortality occurred during follow-up. Three of the patients had no recurrence at the latest follow-up (mean latest follow-up 4.5 years), while one patient had a slight recurrence. PA-CPA can be safely removed, and most complications immediately after surgery resolve in the long-term follow-up.

Successful Surgery of Exophytic Brainstem Glioma Mimicking Cerebellar-Pontine Angle Tumor: Case Report and Review of Literature

BACKGROUND

Nontectal plate exophytic brainstem gliomas with pilocytic histology are rare and occur mainly in children. Because of their eloquent location, therapy usually consists of bioptic histologic verification and radiotherapy in case of progression.

CASE DESCRIPTION

We report on a 43-year-old patient who presented with intermittent tinnitus and reduced hearing in his left ear, as well as a slight left-sided ataxia. Magnetic resonance imaging revealed a left-sided solid cystic cerebellar-pontine angle (CPA) tumor completely obliterating the CPA. Radiologically, a solid cystic vestibular schwannoma was diagnosed. Intraoperatively, a glossy-grayish, intensively bleeding tumor without any capsule or delineation to the brainstem or cranial nerves was resected using electrophysiologic monitoring. Postoperative histology revealed a pilocytic astrocytoma. Three months postoperatively, hearing was preserved (pure tone average-35 dB) and ataxia was equal to what it was preoperatively, gradually becoming better. Postoperative magnetic resonance scans demonstrated a complete resection of the tumor with completely restored brainstem contours.

CONCLUSIONS

Exophytic brainstem gliomas may occur in the CPA and mimic vestibular schwannoma. Complete resection even with preserved hearing without neurologic deterioration may be feasible.

Primary Glioblastoma of Cerebellopontine Angle in Adult Mimicking Acoustic Neuroma

BACKGROUND

Gliomas are usually located in the supratentorial region and are extremely rare at the cerebellopontine angle (CPA). Consequently, gliomas in the CPA are easy to misdiagnose preoperatively.

CASE DESCRIPTION

This paper presents a 55-year-old man with an extraaxial CPA glioblastoma arising from the proximal portion of cranial nerve (CN) VIII. Preoperative imaging findings suggested an acoustic neuroma. The tumor was removed subtotally, and it was completely separated from the brainstem and cerebellum. The histopathologic examination showed a glioblastoma.

CONCLUSIONS

To our knowledge, this case is the second report of a true primary extraaxial CPA glioblastoma. Therefore glioma should be considered in the differential diagnosis of CPA masses with atypical imaging features, although they are extremely rare.

Cerebellopontine Angle Anaplastic Ganglioglioma Masquerading as Vestibular Schwannoma: Unusual Entity

BACKGROUND

Anaplastic gangliogliomas at the cerebellopontine angle (CPA) are exceptionally rare with only a few reported cases in published literature. These are composed of atypical ganglion cells and astrocytes accounting for nearly 1% of all central nervous system tumors. The authors report the case of anaplastic ganglioglioma in an adult patient presenting as a CPA mass lesion. The presentation was bizarre, and the diagnosis was possible only after histopathologic examination of the resected mass.

CASE DESCRIPTION

A 32-year-old lady presented with complaints of gradually progressive hearing loss and tinnitus in her right ear along with headache and ataxia. Neurologic evaluation revealed right-sided sensorineural hearing loss and truncal ataxia. Magnetic resonance imaging of the brain was suggestive of a well-defined, contrast-enhancing, solid-cystic mass at the CPA cistern that extended into the porus acusticus, causing enlargement of the internal acoustic meatus. The features were suggestive of vestibular schwannoma of the CPA.

CONCLUSIONS

This unusual appearance of anaplastic ganglioglioma has not been previously described. Neurosurgeons need to keep in mind the possibility of anaplastic gangliogliomas in the differential diagnosis of CPA lesions.

Pilocytic astrocytoma of the cerebellopontine angle mimicking vestibular schwannoma: report of a rare entity

We present a rare case of a 55-yr old patient of pilocytic astrocytoma of the cerebello-pontine angle mimicking a vestibular schwannoma. The tumor protruded into the porus acusticus causing enlargement of the internal auditory meatus, which is quite an unusual feature of glial tumours.

Profound hearing loss following surgery in pediatric patients with posterior fossa low-grade glioma

Background

Hearing loss may occur in patients with posterior fossa low-grade glioma who undergo surgery.

Methods

We retrospectively reviewed 217 patients with posterior fossa low-grade glioma, including 115 for whom results of hearing tests performed after surgery and before chemotherapy or radiation therapy were available. We explored the association of UHL with age at diagnosis, sex, race, tumor location, extent of resection, posterior fossa syndrome, ventriculoperitoneal shunt placement, and histology.

Results

Of the 115 patients, 15 (13.0%: 11 male, 6 black, 8 white, 1 multiracial; median age 7 years [range, 1.3-17.2 years]) had profound UHL after surgery alone or before receiving ototoxic therapy. Median age at tumor diagnosis was 6.8 years (range, 0.7-14.1 years), and median age at surgery was 6.8 years (range, 0.7-14.1 years). Patients with UHL had pathology characteristic of pilocytic astrocytoma (n = 10), ganglioglioma (n = 4), or low-grade astrocytoma (n = 1). Of these 15 patients, 4 underwent biopsy, 1 underwent gross total resection, 1 underwent near-total resection, and 9 underwent subtotal resection. UHL was more frequent in black patients than in white patients (OR 7.3, P = .007) and less frequent in patients who underwent gross total resection or near-total resection than in those who underwent subtotal resection (OR 0.11, P = .02).

Conclusions

Children undergoing surgery for posterior fossa low-grade glioma are at risk for UHL, which may be related to race or extent of resection. These patients should receive postoperative audiologic testing, as earlier intervention may improve outcomes.

Direct Cranial Nerve Involvement by Gliomas: Case Series and Review of the Literature

Malignant gliomas are characterized by infiltrative growth of tumor cells, including along white matter tracts. This may result in clinical cranial neuropathy due to direct involvement of a cranial nerve rather than by leptomeningeal spread along cranial nerves. Gliomas directly involving cranial nerves III-XII are rare, with only 11 cases reported in the literature before 2014, including 8 with imaging. We present 8 additional cases demonstrating direct infiltration of a cranial nerve by a glioma. Asymmetric cisternal nerve expansion compared with the contralateral nerve was noted with a mean length of involvement of 9.4 mm. Based on our case series, the key imaging feature for recognizing direct cranial nerve involvement by a glioma is the detection of an intra-axial mass in the pons or midbrain that is directly associated with expansion, signal abnormality, and/or enhancement of the adjacent cranial nerves.

Primary glioblastoma of the trigeminal nerve root entry zone: case report

Gliomas of the cranial nerve root entry zone are rare clinical entities. There have been 11 reported cases in the literature, including only 2 glioblastomas. The authors report the case of a 67-year-old man who presented with isolated facial numbness and was found to have a glioblastoma involving the trigeminal nerve root entry zone. After biopsy the patient completed treatment with conformal radiation and concomitant temozolomide, and at 23 weeks after surgery he demonstrated symptom progression despite the treatment described. This is the first reported case of a glioblastoma of the trigeminal nerve root entry zone.

Pediatric sensorineural hearing loss, part 2: syndromic and acquired causes

This article is the second in a 2-part series reviewing neuroimaging in childhood SNHL. Previously, we discussed the clinical work-up of children with hearing impairment, the classification of inner ear malformations, and congenital nonsyndromic causes of hearing loss. Here, we review and illustrate the most common syndromic hereditary and acquired causes of childhood SNHL, with an emphasis on entities that demonstrate inner ear abnormalities on cross-sectional imaging. Syndromes discussed include BOR syndrome, CHARGE syndrome, Pendred syndrome, Waardenburg syndrome, and X-linked hearing loss with stapes gusher. We conclude the article with a review of acquired causes of childhood SNHL, including infections, trauma, and neoplasms.

Primary glioblastoma of the cerebellopontine angle in adults

Gliomas are rare entities in the cerebellopontine angle (CPA) in adults. The authors present clinical, neuroradiological, serological, and neuropathological findings in a 60-year-old man with an extraaxial CPA glioblastoma arising from the proximal portion of cranial nerve VIII. The patient presented with progressive left-sided deafness and left-sided facial palsy lasting less than 2 months and progressive dysarthria and dysphagia lasting 2 weeks. Preoperative neuroimaging suggested the diagnosis of CPA meningioma with "dural-tail" sign and involvement of the internal auditory canal. Serological examination showed an increase in the malignant markers of ferritin and neuron-specific enolase, which suggested underlying malignancy. The tumor was subtotally removed, and it was confirmed to be completely separated from the brainstem and cerebellum. Cranial nerves VII and VIII were destroyed and sacrificed. Transient severe bradycardia occurred during surgery due to entrapment of the caudal cranial nerve complex by the tumor in such an infiltrative way. The neuropathological examination revealed a glioblastoma. The patient underwent no further treatment and died of cachexia 2 months postoperatively. To the authors' knowledge, this represents the first case of a primary glioblastoma in the CPA in an adult. A high index of suspicion along with reliance on clinical assessment, radiological findings, and serum detection of specific malignant markers is essential to diagnose such uncommon CPA lesions.

A Primary Extraosseous Ewing Sarcoma in the Cerebellopontine Angle of a Child: Review of Relevant Literature and Case Report

BACKGROUND AND IMPORTANCE:

We report the occurrence of a primary intracranial extraosseous Ewing sarcoma/peripheral primitive neuroectodermal tumor (EES/pPNET) in the cerebellopontine angle in a child.

CLINICAL PRESENTATION:

A 10-year-old girl presented with symptoms and signs of an infratentorial space-occupying lesion that was confirmed by magnetic resonance imaging and followed up by subtotal surgical resection. Tumor cells displayed membranous expression of CD99, and one of the typical translocations of EES/pPNET (chromosome 22) was demonstrated by cytogenetic analysis.

CONCLUSION:

The literature regarding the histopathological, molecular, radiological, prognostic, and therapeutic features of intracranial EES/pPNET is reviewed, emphasizing the distinction of this entity from the central PNET. Although exceptionally rare, intracranial EES/pPNET should be considered in the differential diagnosis of lesions in the cerebellopontine angle.

In pursuit of prognostic factors in children with pilocytic astrocytomas

OBJECTIVE

This study described a 23-year experience in the treatment of children with pilocytic astrocytomas (piloA) with the aim of identifying putative clinical, histopathological, and/or immunohistochemical features that could be related to the outcome of these patients.

METHODS

Clinical data of 31 patients under 18 years of age with piloA were obtained from 1984 to 2006.

RESULTS

The mean age at the time of surgery was 7.8 +/- 4.2 years (1 to 17 years), and the mean follow-up was 5.7 +/- 5.4 years (1 to 20 years). The most common site of tumor formation was the cerebellum (17), followed by brainstem (4), optic chiasmatic hypothalamic region (4), cerebral hemisphere (3), cervical spinal cord (2), and optic nerve (1). Gross total resection (GTR) was achieved in 23 (74.1%), mainly in those with tumors located in the cerebellum and cerebral hemispheres (P = 0.02). The global mortality rate was 6.4%. Nine patients were reoperated. Rosenthal fibers, eosinophilic granular bodies, microvascular proliferation, and lymphocytic infiltration were observed in most cases. The mean Ki-67LI was 4.4 +/- 4.5%. In all cases, Gal-3 expression in tumor cells was observed with variable staining pattern.

CONCLUSIONS

Aside from GTR, no other clinical, histopathological, or immunohistochemical features were found to be related to the prognosis. We postulate that strict follow-up is recommended if piloA is associated with high mitotic activity/Ki67-LI, or if GTR cannot be achieved at surgery. Tumor recurrence or progression of the residual lesion should be strictly observed. In some aspects, childhood piloA remains an enigmatic tumor.