Pediatric isolated oculomotor nerve schwannoma: a new case report and literature review

Successful surgical treatment of oculomotor palsy due to schwannoma of the cavernous sinus in a 7-year-old girl: a case report

Oculomotor nerve schwannoma in children not associated with neurofibromatosis is a rare disease, with 26 pediatric cases reported so far. There is no established treatment plan. A 7-year-old girl presented with oculomotor nerve palsy. Surgical reduction of the tumor combined with postoperative gamma knife surgery preserved the oculomotor nerve, improved oculomotor nerve function, and achieved tumor control during the observation period of 20 months. The combination of partial surgical resection and gamma knife surgery as a treatment strategy for oculomotor nerve schwannoma resulted in a good outcome.

Schwannoma-associated third nerve palsy: A pediatric case report

Acquired third nerve palsies are infrequently seen in children, but are often associated with serious pathologies. This article presents a pediatric case of tumor-associated, isolated third nerve palsy, which took two years to diagnose. The patient initially presented with an isolated, dilated pupil and progressed over several months to a complete third nerve palsy. In this case, high-resolution neuroimaging eventually led to the diagnosis of a presumed schwannoma as the cause of her third nerve palsy. We review her case, the importance of high-resolution imaging, and management options.

Cisternal oculomotor schwannoma: a rare cause of anisocoria with ptosis in a child

Background

Primary nerve sheath tumor of cranial nerve is a rare intracranial space occupying lesion that most commonly involves vestibular nerve. Oculomotor nerve schwannoma, without neurofibromatosis, is an extremely uncommon entity especially in children. Though any cranial nerve can be involved by schwannoma except I and II nerve as these cranial nerves lack a Schwann cell sheath.

Case presentation

We herein report a 14-year-old boy presenting with an oculomotor schwannoma in the absence of features of neurofibromatosis, manifesting as progressive diplopia, ptosis, and blurring of vision.

Conclusions

Most similar previous case reports in literature reported oculomotor schwannoma in adults, unlike our case. The detection rate of such rare lesions has, however, increased in the last two decades due to neuroimaging advances.

Oculomotor nerve schwannoma: case series and literature review

Oculomotor nerve schwannomas are rare benign cranial nerve tumors. There are only a limited number of reports on this pathology in the literature, and there are currently no established management guidelines that aid providers in deciding on surgical versus nonsurgical management. We assess the published literature on the topic to identify indications for treatment as well as outcome measures (e.g., local control rates, survival rates, and complication rates) that have been reported as associated with the various treatment modalities. We attempt to develop an algorithm for evaluation and treatment of oculomotor nerve schwannomas in order to establish consensus on how these tumors should be treated.

Oculomotor Nerve Palsy Due to Unusual Causes

BACKGROUND

An isolated oculomotor nerve (CN III) palsy is a diagnostic concern because of the potential for serious morbidity or life-threatening causes. We present 5 unusual causes of oculomotor nerve palsy that escaped initial diagnosis in order to raise awareness of their associated features that will facilitate correct diagnosis.

METHODS

This study consisted of a retrospective analysis of clinical features and imaging of 5 patients who were referred for neuro-ophthalmologic evaluation with presumed diagnosis of oculomotor nerve palsy of unknown reasons.

RESULTS

A complete CN III palsy and an inferior division CN III palsy were diagnosed with a schwannoma in the cavernous sinus and orbital apex portion, respectively; a middle-aged woman with aberrant regeneration was found to have a small meningioma; an adult man with ptosis was diagnosed with cyclic oculomotor paresis with spasms; and a patient after radiation was diagnosed with neuromyotonia.

CONCLUSIONS

Localizing the lesion of oculomotor nerve palsy and careful examination of the imaging is crucial. Aberrant regeneration, cyclic pupil changes, and past medical history of amblyopia, strabismus, or radiation are also very helpful for diagnosis.

Schwannoma Masquerading as Recurrent Painful Ophthalmoplegic Neuropathy: A Diagnostic Dilemma

Recurrent painful ophthalmoplegic neuropathy, or ophthalmoplegic migraine, is characterized by recurrent cranial nerve paresis following headache. Imaging may demonstrate cranial nerve enhancement during episodes, but absence of structural lesions is required for diagnosis. [J Pediatr Ophthalmol Strabismus. 2020;57:e68-e70.].

Recurrent Painful Ophthalmoplegic Neuropathy and Oculomotor Nerve Schwannoma: A Pediatric Case Report with Long-Term MRI Follow-Up and Literature Review

Background

Recurrent painful ophthalmoplegic neuropathy (RPON), previously known as ophthalmoplegic migraine (OM), is an uncommon disorder with repeated episodes of ocular cranial nerve neuropathy associated with ipsilateral headache. The age of presentation is most often during childhood or adolescence. MRI has a central role in the assessment of the RPON, especially to distinguish orbital, parasellar, or posterior fossa lesions that mimic symptoms of RPON. Actually, oculomotor nerve tumors may be masquerade as RPON so that MRI follow-ups are required to detect the possibility of tumor etiology.

Case presentation

We report a 16-year-old boy with a 7-year follow-up and multiple brain MRI data, previously diagnosed as OM. The last brain MRI, performed during an acute phase of oculomotor paresis with ipsilateral headache, showed a nodular lesion described as schwannoma of III cranial nerve. Then, we reviewed the literature on OM and RPON in pediatric age with a focus on brain MRI findings.

Conclusions

This review highlights the important role of serial brain MRIs in the long-term follow-up of RPON, especially in the cases with childhood onset, in order to not delay the diagnosis of a possible oculomotor nerve schwannoma.

Prognosis Factor in Oculomotor Schwannoma: A Case of Endoscopic Endonasal Approach and Systematic Review of the Literature

BACKGROUND

We report the first case of oculomotor nerve (ON) schwannoma treatment through an endonasal endoscopic approach. We also review the literature to determine prognosis factors of ON function after treatment.

METHODS

A complete MEDLINE search was undertaken for all articles reporting data for oculomotor schwannoma. We divided the patient population into 2 groups; Group I: patients who conserved or recovered good ON function and Group II: patients with either new, worsening, or unchanged third-nerve palsy at the last available follow-up. We conducted a comparative statistical analysis of data between the 2 groups.

RESULTS

We identified 55 reported cases of ON schwannoma, all of whom were treated with open transcranial surgery, stereotactic radiosurgery, or observation. There were 22 patients in group I and 33 in group II. At admission, 29 patients had complete oculomotor nerve palsy (34.7% in group I and 67.7% in group II; P = 0.02). Surgical treatment was performed in 36 cases. Radiosurgery was performed in 3 cases. Among patients with good preoperative ON function, 34.6% worsened at last follow-up (26.6% after surgery and 50% with observation; P = 0.03). In total, 31% of patients with total or near-total palsy at admission had an improvement of their ON function (all after surgical resection; P = 0.05).

CONCLUSIONS

ON function at admission and surgical resection of schwannoma appears to be a predictive factor of favorable prognosis regardless of location and tumor size. The endonasal endoscopic approach can be used to biopsy tumors in cases in which open surgery is considered too risky, such as cavernous sinus schwannomas.

Pediatric intracranial lower cranial nerve schwannoma unassociated with neurofibromatosis type 2: case report and review of the literature

INTRODUCTION

Pediatric schwannomas are rare, and most of them are associated with neurofibromatosis type 2 (NF2) and usually located in the vestibular nerve. Herein, we present the first pediatric case of intracranial schwannoma derived from the IX/X nerve complex unrelated to NF2.

CASE REPORT

The patient was a 9-year-old boy who presented with a 3-month history of headache and nausea. There was no family history of NF2. Imaging studies revealed a cystic lesion with enhanced wall in the left cerebellomedullary fissure. During the operation, the IX/X nerve complex was strongly adhered to the tumor at the jugular foramen. The tumor was totally excised, and the postoperative MRI demonstrated no residual tumor. Histopathological diagnosis was schwannoma. Genetic analysis revealed no mutation associated with NF2 and schwannomatosis.

CONCLUSION

We reported the first case of pediatric lower cranial nerve schwannoma which was not associated with NF2. The schwannoma should be included as differential diagnosis of pediatric posterior fossa tumors.

Oculomotor Schwannomas: A Systematic Review and Report of Two Pediatric Cases Treated with Fractionated Cyberknife Stereotactic Radiotherapy

OBJECTIVE

Pediatric oculomotor nerve schwannomas are rare and challenging lesions due to the high morbidity associated with surgical intervention and their proximity to critical structures limiting the opportunity for stereotactic radiosurgery. We aim to report and review the novel use of fractionated Cyberknife (Accuray, Inc., Sunnyvale, California, USA) stereotactic radiotherapy in pediatric patients with oculomotor schwannomas.

METHODS

A systematic review of PubMed, Embase, and Cochrane was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Two patients, ages 8 and 10 years, with tumor volumes of 0.1 cm³ and 0.2 cm³, respectively, were treated with fractionated Cyberknife radiotherapy at our institution. A total dose of 45-50 Gy was administered over 25 fractions (1.8-2.0 Gy per fraction) to the 82%-84% isodose line. Serial magnetic resonance imaging was obtained for long-term follow-up (56-58 months).

RESULTS

We found 14 articles published between 1982 and 2018 that reported a total of 18 pediatric patients with intracranial oculomotor schwannomas. No previously described cases of pediatric intracranial oculomotor schwannomas were treated with radiation therapy. In both of our patients, radiographic tumor control was achieved at a mean follow-up of 57 months, with 1 patient displaying a decrease in tumor volume. Neither patient exhibited any worsening of their presenting symptoms, nor did either patient develop any new neurocognitive deficits following treatment.

CONCLUSIONS

Fractionated Cyberknife radiotherapy is an effective and well-tolerated treatment option for intracranial oculomotor nerve schwannomas with excellent tumor control rates, similar to surgical and radiosurgical techniques, while sparing critical surrounding structures.

[Oculomotor nerve neurinomas. Case reports and a literature review]

Oculomotor nerve neurinoma not associated with neurofibromatosis type II is an extremely rare pathology. According to the topography, cisternal, cisternocavernous, cavernous, orbitocavernous, and orbital tumor groups are distinguished. The clinical picture of the disease is characterized mainly by either oculomotor disorders or pyramidal symptoms, depending on the tumor localization. Neurinomas of the oculomotor nerve rarely occur without oculomotor disorders. However, in some patients with these tumors, the third nerve function remains intact. In this paper, we present clinical cases of two patients with oculomotor nerve neurinomas and analyze the relevant literature.

Atypical teratoid/rhabdoid tumor (ATRT) arising from the 3rd cranial nerve in infants: a clinical-radiological entity?

Atypical teratoid/rhabdoid tumor (ATRT) is a rare embryonal tumor of the central nervous system with preponderance in very young children, the majority of whom are younger than 3 years of age at diagnosis. Historically, outcomes of this aggressive disease, even with extensive multimodal therapy, have been dismal. Recent improvements have come from therapies directed exclusively towards ATRT, but misdiagnosis or delays in the correct diagnosis lead to significantly worse survival rates. ATRTs most commonly occur supratentorially but have been described in virtually all central nervous system locations, including the cerebellopontine angle cistern, meninges, and spinal canal, and extradural locations. ATRTs originating from cranial nerves are rare. Here, we describe three cases of solitary ATRT arising from the 3rd cranial nerve (CN III) or close to its origin in the midbrain, all of which presented in patients within 6 months of birth, with isolated unilateral oculomotor nerve palsy and strikingly similar magnetic resonance imaging (MRI) features. These MRI features include IV contrast enhancement, relative T2 hyposignal, and restricted water diffusion on apparent diffusion coefficient images, findings which are consistent with angiogenesis and high cellularity, and hence, suggestive of malignancy. We conclude that ATRT should be placed high on the differential diagnosis list when encountering a young infant presenting with isolated, unilateral 3rd nerve palsy and a small, solitary tumor arising from CN III that demonstrates malignant conventional and diffusion-weighted imaging features on MRI.

[Oculomotor nerve schwannoma in a child: Case report and literature review]

An isolated schwannoma of the oculomotor nerve is rare in children without an associated neurofibromatosis. A 13-year-old girl, with a previous medical history of migraine, was admitted for disabling ophthalmic migraine with oblique diplopia. The clinical examination showed a right incomplete ophthalmoplegia with reduced ipsilateral visual acuity (8/10). There was no particular skin reaction. The MRI revealed a right (isosignal-T1 and isosignal-T2) nodular schwannoma located within the cisternal segment of the oculomotor nerve. The angio-CT performed later confirmed the absence of any vascular malformation. The treatment consisted of analgesics and corticotherapy, with complete regression of symptoms three weeks later and a normal MRI follow-up. Therefore, radiosurgery was not performed.