Schwannoma of the Intermediate Nerve: A Rare Type of Cerebellopontine Angle Tumor (original) (raw)
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Schwannoma of the facial nerve in the cerebellopontine angle presenting with hearing loss
Surgical Neurology, 1989
Lee KS, Britton BH, Kelly DL. Schwannoma of the facial nerve in the cerebellopontine angle presenting with hearing loss. Surg Neurol 1989;32:231-4. Schwannomas of the facial nerve in the cerebellopontine angle are unusual. The authors describe a 43-year-old woman with progressive hearing loss and dizziness who had a small schwannoma of the facial nerve in the cerebellopontine angle without extension into the internal auditory canal. The tumor was completely removed with preservation of facial nerve function. The diagnosis and management of facial nerve schwannomas are discussed.
Skull Base Surgery, 2008
The most common cerebellopontine angle (CPA) tumor is a vestibular schwannoma, but one in five CPA tumors are not vestibular schwannomas. These tumors may require different management strategies. Compared with vestibular schwannomas, symptoms and signs from cranial nerve VIII are less frequent: other cranial nerve and cerebellar symptoms and signs predominate in patients with these less common CPA tumors. Computed tomography and magnetic resonance imaging often show features leading to the correct diagnosis. Treatment most often includes surgery, but a policy of observation or subtotal resection is often wiser. This review provides a structured approach to the diagnosis of nonvestibular schwannoma CPA lesions and also management guidelines.
Facial Nerve Schwannoma of the Cerebellopontine Angle: A Diagnostic Challenge
Skull Base, 2002
Facial nerve schwannomas are rare lesions that may involve any segment of the facial nerve. Because of their rarity and the lack of a consistent clinical and radiological pattern, facial nerve schwannomas located at the cerebellopontine angle (CPA) and internal auditory canal (IAC) represent a diagnostic and therapeutic challenge for clinicians. In this report, a case of a CPA/IAC facial nerve schwannoma is presented. Contemporary diagnosis and management of this rare lesion are analyzed.
Neurosurgery, 1998
Great advances in neuroimaging, intraoperative cranial nerve monitoring, and microsurgical technique have shifted the focus of acoustic neuroma surgery from prolonging life to preserving cranial nerve function in patients. An appreciation of the vascular and cranial nerve microanatomy and the intimate relationship between neurovascular structures and the tumor is essential to achieve optimum results. In this paper the authors analyze the microanatomical variations in location of the facial and cochlear nerves in the cerebellopontine angle (CPA) associated with acoustic neuromas and, additionally, describe the frequency of involvement of surrounding neural and vascular structures with acoustic tumors of varying size. The authors base their findings on their experience treating 1006 consecutive patients who underwent surgery via a retrosigmoid or translabyrinthine approach.
Neurosurgical focus, 2018
OBJECTIVE The authors describe their results using an endoscope as an adjunct to microsurgical resection of inferior vestibular schwannomas (VSs) with extension into the fundus of the internal auditory canal below the transverse crest. METHODS All patients who had undergone middle fossa craniotomy for VSs performed by the senior author between September 2014 and August 2016 were prospectively enrolled in accordance with IRB policies, and the charts of patients undergoing surgery for inferior vestibular nerve tumors, as determined either on preoperative imaging or as intraoperative findings, were retrospectively reviewed. Age prior to surgery, side of surgery, tumor size, preoperative and postoperative pure-tone average, and speech discrimination scores were recorded. The presence of early and late facial paralysis, nerve of tumor origin, and extent of resection were also recorded. RESULTS Six patients (all women; age range 40-65 years, mean age 57 years) met these criteria during th...
Cerebellopontine Angle and Intracanalicular Masses Mimicking Vestibular Schwannomas
Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology, 2014
To describe the clinical and radiographic characteristics in a series of patients with non-vestibular schwannoma cerebellopontine angle (CPA) and intracanalicular (IAC) masses, who underwent microsurgery for presumed vestibular schwannoma (VS). Retrospective case series. Tertiary neurotologic referral center. One thousand five hundred ninety-three patients underwent microsurgery for apparent VS from 2002 to 2013. Of these, 53 patients (3%) were discovered to have a diagnosis other than VS. Middle fossa, translabyrinthine, and retrosigmoid craniotomy. Clinical presentation, radiologic analysis, and histopathology examination. There were 17 facial schwannomas, 15 meningiomas, 9 hemangiomas, 6 lipochoristomas, 3 inflammatory reactions, and one each of lymphoma, glial heterotopia, solitary fibrous tumor, ependymoma, and a non-diagnostic mass. Excluding facial schwannomas, 23 cases were misdiagnosed as VS in the first half of the study period, compared to only 15 cases in the latter half...
A Retrospective Study of Clinical Profile and Surgical Outcomes of Vestibular Schwannomas
IOSR Journals , 2019
Introduction: Vestibular schwannomas manifest with very serious deficits of hearing, facial expression, lower cranial nerve, cerebellar and brain stem functions either preoperatively or as a consequence of surgical intervention. Our objective was to analyze the symptomatology and clinical signs and try to correlate with postoperative outcome and complications in the setting of limited infrastructure, therapeutic and monitoring aids and multi-surgeon involvement with varied spectrum of surgical expertise in a single large tertiary teaching institute. Materials and Methods: A retrospective analysis was done using available discharge summary database. Clinical assessment was done using House Brackmann grading for facial nerve function,puretone audiometry for hearing and MRI Brain imaging [Figures 1]. Size of the tumour was taken as the maximum transverse diameter demonstrated on contrast enhanced MRI brain. All patients underwent retromastoid retrosigmoid suboccipital craniectomy. Patients were placed in supine position with head turned to contralateral side and fixed with Mayo’s head frame [Figure 3]. Retromastoid C shaped incision was taken to reflect suboccipital muscles and overlying fascia and subcutaneous tissue as a single layer. Suboccipital craniectomy was done to expose transverse sinus, sigmoid sinus and their junction [figure 4]. Foramen magnum rim was opened electively. Mastoid air cells were packed with muscle/abdominal fat and bone wax. Initial small dural opening was done in the inferior part to expose and drain CSF from cerebello medullary cistern. Results: A total of 52 patients who were entered in the discharge summary database between January 2012 to April 2019 were included in the study. Headache was the most common presenting symptom [65.4 %] [Table 1]. Hydrocephalus was present in 45.4 % of patients out of which 34.5 % required perioperative CSF diversion procedure. Papilloedema was present in 38.2 % of patients. 21 % patients presented with preoperative lower cranial nerve palsy. The mean tumor size was 4.4 cm. Giant tumours [>4 cm] constituted 74 % of patients [Figure 3]. Only 6 % [n=3] tumours were < 3 cm in size. Cystic Vestibular schwannomas [> 50 % tumour having cystic component] constituted 27 % [n=14]. 4 % [n=2] of patients had bilateral vestibular schwannomas. All patients underwent Retrosigmoid retromastoid suboccipital craniectomy. Conclusion: Hearing loss is the main presenting symptom of vestibular schwannoma. The indication and the timing of tumor resection is dependent on the tumor extension and related necessity of brain stem decompression and on the auditory function. The chances of good outcomes [Facial nerve preservation and post op morbidity] are best when surgery is performed early [smaller size tumours] and when there is good preoperative facial and lower cranial nerve function. As an optimal goal, completeness of resection with functional Facial nerve preservation is formulated and as an acceptable compromise, near total microsurgical resection with functional Facial nerve preservation is suggested
Spontaneous transformation of vestibular schwannoma into malignant peripheral nerve sheath tumor
Asian Journal of Neurosurgery, 2018
Although radiosurgery-induced transformation of vestibular schwannoma (VS) into malignant peripheral nerve sheath tumor (MPNST) is being widely discussed, little attention is paid to the spontaneous transition of these tumors. Although the pathogenesis of this phenomenon remains uncertain, growing number of reported cases might call to notice them. We present a case of a 29-year-old woman who suffered right-sided hearing loss which remained untreated for 4.5 years. Magnetic resonance imaging revealed a right cerebellopontine tumor and the patient underwent tumor removal through retrosigmoid approach. Pathologically, the tumor was benign acoustic schwannoma with increased Ki-67 8%–10%. The tumor relapsed only 6 months later and was removed again-this time it was malignant peripheral nerve sheath tumor MPNST. The patient was treated with stereotactic radiotherapy, but despite that tumor growth was observed again and she underwent the third operation. Later on, tumor progression was no...
Analysis of Nonvestibular Cranial Nerve Schwannomas
The Iranian Journal of Neurosurgery, 2023
Background and Aim: Cranial nerve (CN) schwannomas other than the eighth nerve schwannoma are called nonvestibular cranial nerve schwannomas (NVCNS). This study aims to analyze the clinical profile, distribution, and surgical outcome of the NVCNS. Methods and Materials/Patients: This is a retrospective study analyzing the NVCNS conducted between January 2007 and December 2021. VIIIth cranial nerve schwannomas and conservatively managed NVCNS were excluded from the study. Results: This study included 25 patients with NVCNS. Ten patients (40%) had trigeminal schwannomas, 3(12%) facial nerve schwannomas, 9 (36%) lower cranial nerve (LCN) schwannomas, 1 (4%) vagal schwannoma in neck and 2(8%) hypoglossal schwannomas. Eight patients (32%) were male and 17(68%) were female. The age of the patients ranges from 13 to 62 years (mean 39 years +/-14 SD). Findings of cerebellar involvement, VIIIth CN involvement, and headache are the most common clinical features. The posterior cranial fossa is the most common location of the tumors. Thirteen patients (52%) underwent gross total resection (GTR), 7(28%) underwent neartotal resection (NTR) and 5(20%) underwent subtotal resection (STR). All the patients improved in the postoperative period. Facial nerve palsy is the most common cranial nerve palsy occurring in the postoperative period. Conclusion: Trigeminal and lower cranial nerve (LCN) schwannomas are the most common NVCNS. The retrosigmoid suboccipital approach is the most commonly used surgical approach for tumors located in the posterior cranial fossa. Since NVCNS are benign lesions, postoperative clinical improvement along with decreased complications should be the goal of the surgery. Hence, gross total resection is the most commonly achieved extent of resection, near-total or subtotal resection can be done wherever gross total resection (GTR) is not possible in NVCNS.