[Analysis of the outcome of 12 cases of facial nerve tumors].

Objective:This study aims to provide a comprehensive summary of the pathogenesis, screening modalities, treatment strategies, repair modalities and preliminary results associated with facial nerve tumors. Methods:A retrospective analysis was conducted on the clinical data of 12 patients with facial nerve tumors who were admitted to our department between May 2018 and February 2023. The study population consisted of 5 males and 7 females, with ages ranging from 35 to 90 years. Clinical symptoms observed in these patients included facial nerve palsy, hearing loss, tinnitus, headache, and otalgia, etc. The severity of facial nerve dysfunction was assessed using the House-Brackmann（H-B） facial nerve function classification, with 3 cases classified as grade Ⅰ, 4 cases as grade Ⅲ, 2 cases as grade Ⅳ, and 3 cases as grade Ⅴ. There was a total of 11 patients who presented with hearing loss. Among these patients, 7 cases were diagnosed with conductive hearing loss, 2 cases with sensorineural hearing loss, and 2 cases with mixed hearing loss. The selection of the observation or surgical route for tumor localization was based on clinical symptoms, facial nerve function grading, and imaging examination results including temporal bone CT and enhanced MRI. Specifically, the location of the tumor was selected for observation or the best surgical route: 2 cases were followed up for observation, 1 case underwent biopsy, and 9 cases underwent tumor resection（7 cases of trans-mastoid approach, 2 cases of combined parotid-mastoidal approach）, concurrent repair of the facial nerve（4 cases of auricular nerve grafting, 3 cases of facial nerve diversion anastomosis, 2 cases of peroneal nerve grafting）. （4 cases of auricular nerve graft, 3 cases of facial nerve diversion anastomosis and 2 cases of peroneal nerve grafting）. Periodic postoperative evaluation of facial nerve function was conducted. Results:1-year follow-up was available. Intraoperatively, it was observed that 66.7%（6 out of 9） of the facial nerve tumors were present in multiple segments. Among these segments, the vertical segment had the highest proportion, accounting for 77.8%（7 out of 9）, followed by the labyrinthine segment/geniculate ganglion with 66.7%（6 out of 9） and the horizontal segment with 55.6%（5 out of 9）. Postoperative pathology confirmed 8 cases with nerve sheath meningioma, Ⅰ with seminal fibroma and 1 with hemangioma. Postoperative facial nerve function was graded as H-B grade I in one patient）, grade Ⅲ in three, grade Ⅳ in four, grade Ⅴ in 2, and grade Ⅵ in 2 patients. The auditory outcomes following surgery are as follows: 8 individuals experienced postoperative hearing loss, while 2 individuals demonstrated postoperative hearing preservation. Conclusion:In the case of patients presenting with facial nerve palsy as their initial symptom, it is imperative to consider the potential presence of a facial nerve tumor. To determine the appropriate course of action, it is necessary to ascertain the size and location of the tumors through imaging examinations. This information will aid in the decision making process regarding whether surgical intervention is warranted, and so, the most suitable approach. Additionally, the choice of repair method during the operation should be guided by the extent of facial nerve defect.

Diagnostic Challenges and Imaging Considerations for Intraparotid Facial Nerve Schwannoma: A Case Report and Literature Review.

BACKGROUND A mass in the parotid gland usually indicates parotid gland neoplasia. Warthin tumors or pleomorphic adenomas are common differential diagnoses. Less frequently, other differential diagnoses and sites of origin are considered. Schwannomas are rare, benign tumors in the head and neck region. Even more rarely, these tumors occur in the intraparotid course of the facial nerve. In the following, we report about 2 patients in whom a mass in the right parotid gland was found incidentally during magnetic resonance imaging (MRI). CASE REPORT We reviewed data from the literature on intraparotid facial nerve schwannomas (IPFNS) and compared them with those from our cases. The focus was on data such as clinical history, clinical symptoms, electroneurography, and various imaging modalities, such as ultrasonography and MRI combined with diffusion-weighted imaging. CONCLUSIONS It is challenging to distinguish facial nerve schwannomas from other neoplasms. Patient's history, clinical symptoms, MRI examination with diffusion-weighted imaging, and high-resolution ultrasound imaging are decisive factors for diagnosis and should be performed when IPFNS is suspected. Diagnosis and therapy for IPFNS remain challenging. A wait-and-scan approach could be an option for patients with small tumors and good facial nerve function. On the other hand, patients with advanced tumors associated with limited facial nerve function can benefit from surgical approaches or stereotactic radiosurgery.

Transmaxillary approach for resection of maxillary division trigeminal schwannoma at foramen rotundum.

BACKGROUND: The foramen rotundum and anterior cavernous sinus have traditionally been accessed by transcranial approaches that are limited by the high density of critical neurovascular structures. The transmaxillary approach provides an entirely extradural route to the foramen rotundum and anterior cavernous sinus. METHOD: This patient with neurofibromatosis and facial pain with trigeminal schwannoma at the foramen rotundum was successfully treated by transmaxillary resection of the tumor. This approach allowed for a direct extradural access to the pathology, with bony decompression and tumor resection, avoiding transcranial routes. CONCLUSION: The transmaxillary approach provides a safe and entirely extradural corridor to access smaller localized skull base lesions at and surrounding the cavernous sinus.

Clinical and Imaging Outcomes After Trigeminal Schwannoma Radiosurgery: Results From a Multicenter, International Cohort Study.

BACKGROUND AND OBJECTIVES: An international, multicenter, retrospective study was conducted to evaluate the long-term clinical outcomes and tumor control rates after stereotactic radiosurgery (SRS) for trigeminal schwannoma. METHODS: Patient data (N = 309) were collected from 14 international radiosurgery centers. The median patient age was 50 years (range 11-87 years). Sixty patients (19%) had prior resections. Abnormal facial sensation was the commonest complaint (49%). The anatomic locations were root (N = 40), ganglion (N = 141), or dumbbell type (N = 128). The median tumor volume was 4 cc (range, 0.2-30.1 cc), and median margin dose was 13 Gy (range, 10-20 Gy). Factors associated with tumor control, symptom improvement, and adverse radiation events were assessed. RESULTS: The median and mean time to last follow-up was 49 and 65 months (range 6-242 months). Greater than 5-year follow-up was available for 139 patients (45%), and 50 patients (16%) had longer than 10-year follow-up. The overall tumor control rate was 94.5%. Tumors regressed in 146 patients (47.2%), remained unchanged in 128 patients (41.4%), and stabilized after initial expansion in 20 patients (6.5%). Progression-free survival rates at 3 years, 5 years, and 10 years were 91%, 86%, and 80 %. Smaller tumor volume (less than 8 cc) was associated with significantly better progression-free survival ( P = .02). Seventeen patients with sustained growth underwent further intervention at a median of 27 months (3-144 months). Symptom improvement was noted in 140 patients (45%) at a median of 7 months. In multivariate analysis primary, SRS ( P = .003) and smaller tumor volume ( P = .01) were associated with better symptom improvement. Adverse radiation events were documented in 29 patients (9%). CONCLUSION: SRS was associated with long-term freedom (10 year) from additional management in 80% of patients. SRS proved to be a valuable salvage option after resection. When used as a primary management for smaller volume tumors, both clinical improvement and prevention of new deficits were optimized.

Infiltrative fibrous lesion of the facial nerve mimicking a facial nerve tumor.

PURPOSE: To report three cases of facial nerve lesions that were clinically expected to be facial nerve tumors but showed fibrotic infiltration without any apparent signs of a specific tumor on histopathological findings. We also aimed to investigate the clinical characteristics of these cases. METHODS: Medical records of patients who underwent surgery for facial nerve lesions were reviewed. RESULTS: All three cases initially had House-Brackmann (HB) grade IV-V facial nerve palsy. On radiological imaging, schwannoma or glomus tumor originating from the facial nerve was suspected. All patients underwent complete surgical removal of the neoplasm followed by facial nerve reconstruction using the sural nerve. The lesions were histologically confirmed as infiltrative fibrous lesions without tumor cells. In two cases, facial nerve palsy improved to HB grade III by nine months post-surgery, and there were no signs of recurrence on follow-up MRI. The other case, after 1 year of follow-up, showed persistence of HB grade V facial nerve palsy without any evidence of recurrence. CONCLUSION: Fibrotic lesions of the facial nerve could mimic primary facial nerve tumors. Clinicians should consider this condition even when a facial nerve tumor is suspected.

Endoscopic Transorbital Surgery for Trigeminal Schwannoma: Introduction of a Novel Approach: 2-Dimensional Operative Video.

INDICATIONS CORRIDOR AND LIMITS OF EXPOSURE: The major indications of endoscopic transorbital approach include spheno-orbital meningiomas, cavernous sinus lesions, and Meckel cave lesion such as trigeminal schwannomas. It can avoid excessive brain retraction and allows for a fast recovery to the normal daily living activity. ANATOMIC ESSENTIALS NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT: To access the cavernous sinus, the sagittal crest and meningo-orbital band should be identified and cut. ESSENTIAL STEPS OF THE PROCEDURE: 1. Skin incision along the superior eyelid is performed. 2. Careful dissection of the soft tissue under the orbicularis is required not to injure the orbital septum. 3. After the lateral orbital rim is exposed, the periosteum and periorbita are elevated from the lateral orbital wall. 4. Drilling of the zygomatic bone within the orbit exposes the temporalis muscle first followed by the exposure of the temporal dura. It is essential to obtain adequate working room when the base of the greater sphenoidal wing is drilled. The sagittal crest should be removed, and the meningo-orbital band should be cut to expose the lateral cavernous sinus wall. PITFALLS/AVOIDANCE OF COMPLICATIONS: For successful access through the orbit, endoscopic transorbital approach needs to minimize the retraction of the orbit. To achieve this goal, retraction of the orbit should be limited to a maximum of 10 minutes. VARIANTS AND INDICATIONS OF THEIR USE: This approach can be combined with lateral orbitotomy. It provides a wider working room and makes surgery easier to access the lateral temporal lobe.The patient consented to the procedure, and the participants and any identifiable individuals consented to publication of his/her image. Images at 1:29 reproduced from Corrivetti F, de Notaris M, Di Somma A, et al, "Sagittal crest": definition, stepwise dissection, and clinical implications from a transorbital perspective, Operative Neurosurgery , 22(5), p e206-e212, ©2022, by permission from the Congress of Neurological Surgeons. Video screen capture from The Neurosurgical Atlas at 1:06 used with permission from Aaron Cohen-Gadol; ©The Neurosurgical Atlas, all rights reserved.

Characteristics and Management of Facial Nerve Schwannomas and Hemangiomas.

OBJECTIVES: To characterize facial nerve (FN) schwannomas (FNSs) and FN hemangiomas (FNHs) and their clinical features and management strategies, and to describe the results of cable nerve grafting after FN sectioning during tumor removal. METHODS: This retrospective study included 84 FNS cases and 42 FNH cases managed between July 1989 and July 2020 at a quaternary referral center for skull base pathology. Clinical details, locations, management, and results of cable nerve grafting at 1 year and during an average period of 3.12 years were evaluated. Sural nerve interpositioning was performed for patients who experienced FN paralysis for less than 1 year and underwent nerve sectioning during tumor removal. RESULTS: FNSs more often involved multiple segments compared with FNHs. The cerebellopontine angle and the mastoid segments were involved in 16 (19.1%) and 34 (40.5%) FNS cases, respectively; however, the cerebellopontine angle and the mastoid segments were involved in 0 and 7 (16.7%) FNH cases, respectively. Sectioned nerves of 99 patients (78.6%) were restored using interposition cable grafting. At the last follow-up evaluation, 56.3% of FNSs and 60.7% of FNHs attained House-Brackmann (HB) grade III. Lower preoperative HB grades were associated with poorer postoperative outcomes. For FNSs, the mean HB grades were 4.13 at 1 year postoperatively and 3.75 at the last follow-up evaluation ( p = 0.001); however, for FNHs, the mean HB grades were 4.04 postoperatively and 3.75 at the last follow-up evaluation. Therefore, extradural coaptation yielded better outcomes. CONCLUSION: FNSs can occur along any part of the FN along its course, and FNHs are concentrated around the area of geniculate ganglion. The results of cable inter positioning grafts are better in patients with preoperative FN-HB-III or less when compared with higher grades. The outcome of the interpositioning continues to improve even after 1 year in extradural coaptation.

An unexpected complication of hypoglossal schwannoma surgery: Cerebrospinal fluid leakage-A case report and literature review.

BACKGROUND: Extracranial hypoglossal schwannoma is a rare tumor primarily treated with surgical excision. This article aims to highlight the potential for unexpected complications intraoperatively, such as cerebrospinal fluid leakage from skullbase to neck. METHODS: A previously healthy 23-year-old male presented with tongue numbness. Magnetic resonance imaging revealed a 17 × 20 mm nodular lesion adjacent to the cervical segment of the internal carotid artery. Surgical excision was scheduled due to suspicion of a neurogenic tumor. RESULTS: Intraoperatively, despite careful handling, cerebrospinal fluid leakage was observed. Manipulation of the mass caused detachment of proximal nerve fibers, potentially indicating avulsion of the hypoglossal nerve from the brainstem or nearby. Clear fluid leakage from the skull base was also noted. CONCLUSION: Thorough preoperative evaluation and patient education regarding potential complications are crucial. This article presents an unexpected complication encountered during surgical excision of extracranial hypoglossal schwannoma, emphasizing the need for awareness and preparedness in such cases.

Operative management of trigeminal schwannomas: based on a modified classification in a study of 93 cases.

BACKGROUND: Advances in microscopic and endoscopic surgical techniques have outpaced traditional classification and transcranial surgical strategies, especially with reference to the treatment of trigeminal schwannomas (TSs). A modified TS classification is proposed and appropriate surgical strategies are discussed. METHODS: The cases of 93 patients who underwent surgical treatment in Beijing Tiantan Hospital in the previous 6 years were analyzed retrospectively, and a literature review was conducted. RESULTS: Classification is based on surgical direction. Tumors were classified as follows: type A, backward orientation, located in the orbit or orbit and middle cranial fossa (8 cases, 8.6%); type B, upward orientation, located in the pterygopalatine fossa, infratemporal fossa or pterygopalatine fossa, infratemporal fossa, and middle cranial fossa (23 cases, 24.7%); type C, forward and backward orientations, located in the middle cranial fossa, posterior cranial fossa or both (58 cases, 62.4%); and type D, located in multiple regions (4 cases, 4.3%). 91.40% of patients underwent gross total resection (GTR) with 29 cases receiving endoscopic resection of whom 93.10% (27/29) experienced GTR. CONCLUSION: The 93 cases were satisfactorily divided into four types, according to tumor location and surgical orientation, enabling safe and effective removal by appropriate surgery.

What is new in intraneural perineurioma?

Since the initial description of intraneural (IN) perineurioma in 1964, advances in the understanding of the clinical presentation, diagnostic imaging, pathologic features, and genetic underpinnings have changed how this pathology is managed. IN perineuriomas are rare, benign peripheral nerve sheath tumors, most frequently coming to clinical attention when patients present with painless, progressive weakness or sensory loss in adolescence or young adulthood. The gold standard of diagnosis has traditionally been with targeted tissue biopsy demonstrating "pseudo-onion bulb" formation with positive epithelial membrane antigen (EMA) staining. However, modern magnetic resonance imaging is allowing some patients to forgo biopsy. Recent genetic studies of IN perineuriomas have demonstrated common TRAF7 point mutations and rare NF2 mutations, which may present targets for diagnosis or therapy in the future. Current advances have allowed for us to provide improved patient counseling with informed understanding for various clinical scenarios. With the workup and diagnosis now clearly defined, the next frontier is for improving the lives of patients with IN perineuriomas through the interaction between restoration of functional deficits and advances in our understanding of the genetics of this entity.

Predictors of Surgical Outcomes in Patients with Abducens Nerve Schwannoma: A Comprehensive Systematic Review and a Case Report.

BACKGROUND: Abducens nerve (AN) schwannomas are extremely rare tumors. Clinical characteristics and factors that influence postoperative outcomes are not well defined. OBJECTIVE: To characterize clinical features of AN schwannomas and predictors of surgical outcomes. METHODS: PRISMA-guided systematic review of the literature on AN schwannomas was performed. Subsequently, univariate and multivariate regression analyses were performed to identify the predictive value of variables that influence postoperative outcomes. RESULTS: A total of 42 studies with 55 patients were evaluated. The mean age at presentation was 43.9 ± 14.6 years. The most common presenting symptom was cranial nerve VI palsy (69.1%). Cavernous sinus (49.1%) and prepontine cistern (36.3%) were the most commonly involved locations. Complete recovery after surgery was seen in 36.3% at a median follow-up of 28.4 ± 25.8 months. Preoperative AN palsy (P < 0.001), suboccipital approach (P = 0.007), and subtotal resection of tumor (P = 0.044) were significant protective factors for postoperative complications. Prepontine location and postoperative complications were poor prognostic indicators of AN recovery (odds ratio [OR], 0.10, P = 0.030 and OR, 0.10, P = 0.028, respectively). Subtotal resection was significantly correlated with higher odds of AN recovery (OR, 6.06; P = 0.040). CONCLUSIONS: AN schwannomas are rare but serious tumors that can cause significant morbidity, with only approximately one third of patients showing complete recovery after surgery. The suboccipital approach was a protective factor for postoperative complications, especially when combined with subtotal resection. Knowledge of these factors along with tumor characteristics helps optimize surgical planning and preoperative counseling.

Outcomes following surgical resection of trigeminal schwannomas: a systematic review and meta-analysis.

Although typically benign, trigeminal schwannomas (TS) may require surgical resection when large or symptomatic and can cause significant morbidity. This study aims to summarize the literature and synthesize outcomes following surgical resection of TS. A systematic review was performed according to PRISMA guidelines. Data extracted included patient and tumor characteristics, surgical approaches, and postoperative outcomes. Odds ratios (OR) with corresponding 95% confidence intervals (CI) were used for outcome analysis. The initial search yielded 1838 results, of which 26 studies with 974 patients undergoing surgical resection of TS were included. The mean age was 42.9 years and 58.0% were female. The mean tumor diameter was 4.7 cm, with Samii type A, B, C, and D tumors corresponding to 33.4%, 15.8%, 37.2%, and 13.6%, respectively. Over a mean symptom duration of 29 months, patients presented with trigeminal hypesthesia (58.7%), headache (32.8%), trigeminal motor weakness (22.8%), facial pain (21.3%), ataxia (19.4%), diplopia (18.7%), and visual impairment (12.0%). Surgical approaches included supratentorial (61.4%), infratentorial (15.0%), endoscopic (8.6%), combined/staged (5.3%), and anterior (5.7%) or posterior (4.0%) petrosectomy. Postoperative improvement of facial pain (83.9%) was significantly greater than trigeminal motor weakness (33.0%) or hypesthesia (29.4%). The extent of resection (EOR) was reported as gross total (GTR), near total, and subtotal in 77.7%, 7.7%, and 14.6% of cases, respectively. Over a mean follow-up time of 62.6 months, recurrence/progression was noted in 7.4% of patients at a mean time to recurrence of 44.9 months. Patients with GTR had statistically significantly lower odds of recurrence/progression (OR: 0.07; 95% CI: 0.04-0.15) compared to patients with non-GTR. This systematic review and meta-analysis report patient outcomes following surgical resection of TS. EOR was found to be an important predictor of the risk of recurrence. Facial pain was more likely to improve postoperatively than facial hypesthesia. This work reports baseline rates of post-operative complications across studies, establishing benchmarks for neurosurgeons innovating and working to improve surgical outcomes for TS patients.

Comparative Analysis of Surgical Working Corridors for Meckel Cave Trigeminal Schwannomas: A Quantitative Anatomic Study.

BACKGROUND AND OBJECTIVES: Volumetric analysis of the working corridors of the interdural approach to the Meckel cave may lead to a selection of routes which are anatomically more advantageous for trigeminal schwannoma resection. The herein-reported anatomic study quantitively compares the infratrochlear (IT) transcavernous, anteromedial (AM), and anterolateral (AL) corridors, highlighting their feasibility, indications, advantages, and limitations. METHODS: Anatomic boundaries and depth of Meckel cave, porus trigeminus, IT transcavernous, AM, and AL corridors were identified in 20 formalin-fixed latex-injected cadaveric heads and were subsequently measured. The corridor areas and volumes were derived accordingly. Each opening angle was also calculated. Angles and volumes were compared using analysis of variance. Statistical significance was set at a P -value <.05. RESULTS: The IT transcavernous corridor volume was greater than that of the AM and AL. The opening angle of the AM middle fossa triangle was wider than the other 2. CONCLUSION: The IT corridor can be advantageous for Meckel cave schwannomas invading the cavernous sinus and those with a notable extension into the posterior fossa because the transcavernous approach maximizes the working space into the retrosellar area. The AM middle fossa corridor is strategic in schwannomas confined to the Meckel cave with a minor extension into the posterior fossa. It raises the chance of total resection with a single approach involving the porus trigeminus opening.

Facial Nerve Tumors in Children: Two Clinical Cases and a Review of the Literature.

We provide an extensive review of clinical features, diagnosis, and treatment of primitive facial nerve tumors in children, and report 2 recent personal observations. We conducted a comprehensive literature search through PubMed, Medline, and ScienceDirect and collected information on patients' age, symptoms, tumor types and sites, diagnostic procedures, surgical approaches, and outcomes. Overall, we reviewed 26 pediatric cases from 20 papers. About 69.2% of children presented with some degree of facial palsy. Other symptoms included hearing loss, dizziness, and tinnitus. 84.6% of tumors were schwannomas, followed by meningiomas, epithelioid hemangioendothelioma, and germ cell tumors. The geniculate ganglion was the most commonly affected segment of the facial nerve. A total of 92.3% of children received surgery as complete or partial tumor resection. Facial nerve function improved in 26.9% of children. No tumor recurrence was reported. Facial nerve tumors are extremely rare in children but should be considered in the differential diagnosis of facial palsy, even in newborns. Audiometric and radiologic examinations are necessary; radiologic imaging allows to determine tumor localization, and the correct surgical approach surgery is suggested in almost all cases.

Report of a vagal paraganglioma at the cervicothoracic junction.

BACKGROUND: Vagus nerve paragangliomas are rare tumors, comprising 0.03% of head and neck neoplasms. These tumors are usually located cephalad to the hyoid bone, and there is only one previously reported case that arose from the lower third of the neck. METHODS: We describe the second reported case of a lower neck vagus nerve paraganglioma that was managed with a limited sternotomy for access and surgical removal. RESULTS: A 66-year-old male presented with a long-standing lesion of the cervicothoracic junction. CT, MRI, and Ga-68 DOTATATE PET/CT showed an avidly enhancing 5.2 × 4.2 × 11.5 cm mass extending from C6 to approximately T4 level. FNA confirmed the diagnosis. The patient underwent catheter angiography and embolization via direct puncture technique followed by excision of the mass via a combined transcervical and limited sternotomy approach. CONCLUSION: We describe an unusual case of vagal paraganglioma at the cervicothoracic junction with retrosternal extension requiring a sternotomy for surgical excision.

Perisellar Tumor Coexisting with Unruptured Cerebral Aneurysm: Single-Stage or Staged Surgery?

OBJECTIVE: The coexistence of perisellar tumors and intracranial aneurysms was previously considered a rare phenomenon. In this study, we introduce our experience with surgical strategies for the treatment of such coexisting pathologies. METHODS: This retrospective study reviews the medical records and intraoperative videos of patients with coexisting pathologies of perisellar tumors and aneurysms from Nov 2017 to Oct 2022. RESULTS: Our study involved 20 patients, including 9 males and 11 females. Three patients selected the single-stage endoscopic endonasal approach (EEA), including one with a type of MP trigeminal schwannoma with an anterior communicating aneurysm, 1 with a pleomorphic xanthoastrocytoma with a left internal carotid artery paraclinoid aneurysm, and 1 with a recurrent pituitary adenoma with a right internal carotid artery paraclinoid aneurysm. Thirteen patients chose tumor resection first through the EEA with embolization or aneurysm conservation. There were also 2 patients with irregularly shaped aneurysms who chose embolization before tumor resection. All tumors were completely removed, with only a few patients experiencing recurrence and postoperative complications, and the follow-up of the aneurysms was also stable. There were also 2 patients who chose conservative management for both tumors and aneurysms, but unfortunately, one of them suffered from aneurysm rupture and eventually died. No cerebrospinal fluid rhinorrhea, severe intracranial infection, or surgical-related hemorrhage was found in any patients. CONCLUSIONS: Staged surgery or conservative treatment for aneurysms can be considered a safe and effective strategy for the treatment of coexisting pathologies. However, in very selected cases, the single-stage EEA can be used as part of a comprehensive treatment for such coexisting pathologies.

Endoscopic far-lateral supracerebellar infratentorial approach for resection of dumbbell-shaped trigeminal schwannoma: surgical techniques and preliminary results.

BACKGROUND: Trigeminal schwannomas (TSs) are mostly benign tumors. However, dumbbell-shaped TSs are most challenging for surgeons and pose a high surgical risk. OBJECTIVE: We describe the technique of the purely endoscopic far-lateral supracerebellar infratentorial approach (EFL-SCITA) for removing dumbbell-shaped TSs and further discuss the feasibility of this approach and our experience. METHODS: EFL-SCITA was performed for resection of 5 TSs between January 2020 and March 2023. The entire procedure was performed endoscopically with the goal of total tumor resection. During the operation, the tumor was exposed in close proximity and multiple angles under the endoscope, and the peri-tumor nerves were carefully identified and protected, especially the normal trigeminal fiber bundles around the tumor. RESULTS: All the tumors of 5 patients involved the middle and posterior cranial fossa, of which total removal was achieved in 2 patients and near-total removal in 3 patients. The most common preoperative symptoms were relieved after surgery. Two patients had postoperative mild facial paralysis (House-Brackmann grade II), and 1 patient had abducens palsy; both recovered during the follow-up period. Two patients experienced new postoperative facial hypesthesia, and 1 experienced mastication weakness, which did not recover. There was no tumor recurrence or residual tumor growth during the follow-up period in any of the patients. CONCLUSION: EFL-SCITA is a new and effective alternative for the surgical treatment of TSs. For dumbbell-shaped TSs, this approach provides sufficient surgical field exposure and freedom of operation.

Facial nerve schwannoma and other benign neoplastic facial nerve lesions.

PURPOSE OF REVIEW: Several neoplastic lesions may originate from facial nerves, including facial nerve schwannomas. These neoplastic lesions can cause various symptoms, such as facial nerve paralysis, and decrease the quality of life of patients. Therefore, knowledge of how to manage these diseases is important for otologists. However, the incidence of these diseases is extremely low, and universal management methods have not yet been established. This review summarizes recent advances in knowledge regarding these neoplastic lesions, especially facial nerve schwannomas. RECENT FINDINGS: Recent advances and the accumulation of knowledge regarding these benign facial nerve lesions have provided several preferable treatments and management methods, especially for facial nerve schwannomas. However, this still depends on the patient's symptoms and tumor localization. SUMMARY: This review presents the optimal treatment protocol and differential diagnosis of benign facial nerve lesions. This may be useful for pretreatment differentiation and treatment decision-making.