Long-term analysis of ABI auditory performance in patients with neurofibromatosis type 2-related schwannomatosis.

PURPOSE: This retrospective monocentric study aimed to evaluate long-term auditory brainstem implant (ABI) function in patients with neurofibromatosis type 2, and to investigate the prognostic factors for ABI use. METHODS: Between 1997 and 2022, 27 patients with at least five years of follow-up underwent implantation with 32 ABIs. At 1- and 5-years post-implantation and at last follow-up, ABIs were classified as used or non-used and the size of the ipsilateral tumor was recorded. For patients who used their ABIs, we assessed speech perception (disyllabic words, MBAA sentences) in quiet conditions with the ABI only, by lip-reading (LR), and with a combination of the two (ABI + LR). Hearing improvement was calculated as Δ ABI = (ABI + LR)-LR scores. Predictive factors for ABI use were analyzed. RESULTS: One year post-implantation, 74% patients were ABI-users and 66% of the ABIs were used. Two of these patients were non-users at five years, and another two at last follow-up (14 ± 5.2 years); 54% of the patients were ABI-users at last follow-up. Δ ABI revealed a hearing improvement of 32-41% (disyllabic words) and 28-37% (MBAA sentences). Among 16 ABIs with at least LR improvement at 1-year post-implantation, 4 decreased their performance, coinciding with a large growing ipsilateral tumor in 3/4 ABIs. We identified no significant prognostic factors for ABI use. CONCLUSIONS: ABIs are indicated in case of bilateral deafness with a non-functional cochlear nerve. Half the patients with ABIs used their implants and auditory performance remained stable over time, except in cases of ipsilateral tumor growth.

Recurrence of spinal schwannomas in a patient with neurofibromatosis type 1: a case report.

Introduction and importance: Spinal schwannomas are benign tumors usually attached to peripheral nerves, consisting of a clonal population of Schwann cells. Neurofibromatosis type 1 is an autosomal dominant neurocutaneous disorder that predominantly affects the skin, bone and nervous system. Neurofibromatosis type 1 is a clinically and genetically distinct from neurofibromatosis type 2. This case report highlights the rare association between spinal schwannoma and neurofibromatosis type 1. Case presentation: The patient with a past medical history of spinal schwannoma, operated 1 year back, presented with back pain, weakness of lower limbs and urge incontinence. On examination, she had cutaneous features suggestive of neurofibromatosis type 1 and there was impairment of all sensory modalities below hip region. MRI revealed spinal schwannoma at D9 level for which laminectomy with removal of schwannoma was performed. Clinical discussion: The occurrence and recurrence of spinal schwannoma in neurofibromatosis type 2 is a common finding. But such an association has not been established between spinal schwannoma and neurofibromatosis type 1. In this case, the recurrence of spinal schwannoma has been linked to neurofibromatosis type 1 in the absence of other well-defined etiologies. Conclusion: The occurrence of spinal schwannoma can be genetic or sporadic. The recurrence is usually associated with familial tumor syndrome. The available literature has not established association between neurofibromatosis type 1 and spinal schwannoma, thus, emphasizing the need of more focused studies.

Excision of large median and ulnar nerve schwannomas: a case series.

OBJECTIVE: Schwannomas are benign, slow-growing tumors originating from Schwann cells in peripheral nerves, commonly affecting the median and ulnar nerves in the forearm and wrist. Surgical excision is the gold standard treatment. This study presents our treatment strategies and outcomes for large-sized ulnar and median nerve schwannomas at the forearm and wrist level. METHODS: From 2012 to 2023, we enrolled 15 patients with schwannomas over 2 cm in size in the median or ulnar nerve at the forearm and wrist. The study included 12 patients with median nerve schwannomas (mean age: 61 years) and 3 with ulnar nerve schwannomas (mean age: 68 years), with a mean follow-up of 26.9 months. RESULTS: After surgery, all patients with median nerve schwannomas experienced mild, transient numbness affecting fewer than two digits, resolving within six months without motor deficits. Ulnar nerve schwannoma excision caused mild numbness in two patients, also resolving within six months, but all three developed ulnar claw hand deformity, which persisted but improved at the last follow-up. Despite this, patients were satisfied with the surgery due to relief from severe tingling pain. CONCLUSIONS: Schwannomas of the median, ulnar, and other peripheral nerves should be removed by carefully dissecting the connecting nerve fascicles to avoid injury to healthy ones. Sensory deficits may occur but are unlikely to significantly impact quality of life. However, in motor-dominant nerves like the ulnar nerve, there is a risk of significant motor deficits that could affect hand function, though not completely. Therefore, thorough preoperative discussion and consideration of interfascicular nerve grafting are essential.

Detecting endolymphatic hydrops in patients with cranial nerve VIII schwannoma using hydrops MR examination.

PURPOSE: This study utilized Hydrops MRI in patients with cranial nerve (CN) VIII schwannoma to assess the concomitance with endolymphatic hydrops (EH), aiming to elucidate the mechanism of hydrops formation in these patients. METHODS: Twenty-six patients diagnosed as CN VIII schwannoma including vestibular schwannoma (VS) in 24 and intracochlear schwannoma (ICS) in 2 were enrolled. Fifteen patients received radiosurgery and 11 patients opted for a wait-and-scan approach. All patients underwent an inner ear test battery, followed by Hydrops MRI. Based on Hydrops MRI, 6 patients (23%) with positive EH were assigned to Group A, while the other 20 patients showing negative EH were assigned to Group B. RESULTS: The abnormality rates of inner ear test battery in Group A ran from the audiometry (100%), cervical vestibular-evoked myogenic potential (cVEMP) test (83%), ocular VEMP (oVEMP) test (67%) to the caloric test (33%), exhibiting a significantly declining sequence. This declining sequence is consistent with the decreasing order in the prevalence of EH from the cochlea (83%), saccule (50%) to utricle (50%). However, Group B did not show such decreasing trend, indicating that Groups A and B did not share the common mechanism. The mean tumor size prior to radiosurgery was 1.91 ± 0.89 cm, which significantly reduced to 1.53 ± 0.60 cm at a mean interval of 6 years following radiosurgery. In contrast, tumor size remained unchanged in those opted for a wait-and-scan approach. CONCLUSION: It is recommended to utilize Hydrops MRI for patients with CN VIII schwannoma during annual follow-up, particularly those experienced episodic vertigo and/or deteriorated hearing. The Hydrops MRI can not only monitor tumor size, but also detect the presence of EH, so as to guide treatment decision.

Case Report: Adrenal schwannoma associated with ganglioneuroma.

Background: An adrenal collision tumor (ACT) denotes the presence of distinct tumors with diverse behavioral, genetic, and histological features independently co-existing within the adrenal tissue without intermingling, and occurrences of such cases are infrequent. The concurrent occurrence of adrenal schwannoma and adrenal ganglioneuroma is exceedingly rare, and the diagnosis of these ACTs has been notably challenging due to their atypical clinical manifestations and imaging characteristics. Case summary: A 37-year-old man presented to the hospital 3 weeks after a computed tomography (CT) examination that revealed a left adrenal mass. Physical examination findings were unremarkable. Both CT and magnetic resonance imaging scans indicated the presence of a left adrenal mass. Plasma cortisol, adrenocorticotropic hormone, and renin-angiotensin-aldosterone system tests yielded normal results. Preoperative imaging confirmed the diagnosis of left adrenal pheochromocytoma. After thorough surgical preparation, a laparoscopic partial left adrenalectomy was performed. Subsequent postoperative pathological analysis identified adrenal schwannoma in conjunction with adrenal ganglioneuroma. The patient recovered well and was discharged on postoperative day 4. A routine urology clinic visit was included in his postoperative care plan. During follow-up assessments, CT scans of the left adrenal gland revealed no abnormalities. Conclusion: Adrenal schwannoma combined with ganglioneuroma represents an exceptionally rare collision tumor characterized by the absence of typical clinical or imaging features, leading to potential misdiagnosis. Adrenal incidentalomas present as multifaceted conditions, and this case serves to heighten awareness of their intricate nature. Due to the challenges in preoperative differentiation of various adrenal mass types, postoperative pathological analysis is imperative for guiding the subsequent treatment course for the patient.

Development and application of explainable artificial intelligence using machine learning classification for long-term facial nerve function after vestibular schwannoma surgery.

PURPOSE: Vestibular schwannomas (VSs) represent the most common cerebellopontine angle tumors, posing a challenge in preserving facial nerve (FN) function during surgery. We employed the Extreme Gradient Boosting machine learning classifier to predict long-term FN outcomes (classified as House-Brackmann grades 1-2 for good outcomes and 3-6 for bad outcomes) after VS surgery. METHODS: In a retrospective analysis of 256 patients, comprehensive pre-, intra-, and post-operative factors were examined. We applied the machine learning (ML) classifier Extreme Gradient Boosting (XGBoost) for the following binary classification: long-term good and bad FN outcome after VS surgery To enhance the interpretability of our model, we utilized an explainable artificial intelligence approach. RESULTS: Short-term FN function (tau = 0.6) correlated with long-term FN function. The model exhibited an average accuracy of 0.83, a ROC AUC score of 0.91, and Matthew's correlation coefficient score of 0.62. The most influential feature, identified through SHapley Additive exPlanations (SHAP), was short-term FN function. Conversely, large tumor volume and absence of preoperative auditory brainstem responses were associated with unfavorable outcomes. CONCLUSIONS: We introduce an effective ML model for classifying long-term FN outcomes following VS surgery. Short-term FN function was identified as the key predictor of long-term function. This model's excellent ability to differentiate bad and good outcomes makes it useful for evaluating patients and providing recommendations regarding FN dysfunction management.

Intrabronchial schwannoma with right lower lobe obstructive bronchiectasis and organizing pneumonia: A case report.

We present the case of a 60-year-old female patient with no prior history of any systemic disease. She suffered from a prolonged cough that lasted more than 3 months, associated with poor appetite and weight loss of 5 kg. The pathology report of the pre-operative transbronchial needle biopsy was consistent with a neurogenic tumour. Chest computed tomography (CT) revealed a right lower lobe (RLL) mass-like consolidation of 8.67 cm with obstructive pneumonitis and suspicious posterior mediastinal invasion. The tumour was surgically resected with bronchial reconstruction, and the pathological diagnosis was intrabronchial schwannoma located inside the bronchus, a rare tumour that should be included as one of the differential diagnoses of primary bronchial tumours. The possibility of a surgical completed resection should be considered in patients with airway obstruction symptoms.

A rare simultaneous coexistence of pancreatic gastrointestinal stromal tumor and esophageal schwannoma: a case report and review of literature.

The concurrent presence of gastrointestinal stromal tumor and schwannoma is extremely rare, and its pathological characteristics remain unclear. This case report reported the diagnostic and treatment process of a patient with a pancreatic GIST coexisting with esophageal schwannoma, who was admitted to West China Hospital (Sichuan, China) in April 2015. The patient did not undergo surgical resection of the tumor but instead received an 8-year regimen of imatinib therapy, during which no tumor progression was observed. However, the patient developed pleural effusion as a result of the localized enlargement of the esophageal schwannoma, which exerted pressure on the right inferior pulmonary vein. This case report provides valuable clinical insights into this distinctive disease presentation.

Current approaches to facial nerve schwannoma surgery.

Background: Facial nerve schwannomas (FNSs) are exceedingly rare benign tumors. This study aims to report on a series of excised FNSs, providing clinical information and details on their surgical management, including novel approaches. Methods: We retrospectively reviewed patients who underwent surgical excision of FNSs in a private otology clinic and public tertiary referral center. The main outcome measures were facial nerve function, complete tumor removal, postoperative complications, tumor recurrence, and hearing. Results: Seventeen patients (10 men and 7 women) with a mean age of 44.23 years (SD, 12.21) underwent surgery during the study period. The most common symptom was facial nerve dysfunction (58.8%). Facial and otoneurologic symptoms (hearing loss, tinnitus, and vertigo) were observed in 88.8% and 77.7% of patients, respectively. The middle cranial fossa (MCF) was the most common approach (six patients, 35.2%), followed by translabyrinthine (TL), transmastoid (TM), and combined TM-MCF (three patients, 17.6% each). Exclusive endoscopic transcanal suprageniculate (ETS) and mastoid combined with cervical approaches were applied once in two patients, 5.8% each. Total tumor removal was achieved in all cases. No significant postoperative complications were observed. The mean follow-up period was 193.2 months (SD, 119.5) and no tumor recurrence was observed. Conclusion: This study provides further evidence for the safety and efficacy of various surgical approaches for FNS, and incorporates the endoscopic transcanal approach. Level of evidence: 4.

Multiple sporadic schwannomas in a previously radiated field.

Peripheral nerve sheath tumors are a heterogenous group of predominantly benign tumors of neurogenic origin that arise outside of the central nervous system and include schwannomas and neurofibromas. These tumors often occur sporadically, however multiple lesions are generally associated with genetic syndromes such as neurofibromatosis (type 1 and 2) and schwannomatosis, and occasionally these tumors and their malignant variations are associated with a history of radiation treatment. Multiple benign schwannomas in an irradiated field have seldom been reported in the literature. We describe a case of a 49-year-old male with a history of right sided irradiated testicular cancer who presented with 2 histologically confirmed benign schwannomas in the right pelvic wall and right psoas muscle.

Rare case of Lingual Nerve Schwannoma Presenting as Submandibular Area Swelling with Parapharyngeal Extension.

Schwannoma is a rare benign encapsulated nerve sheath tumor which originates from Schwann cells. Generally, schwannoma arising from lingual nerve involves the oral tongue and tongue base in the oral cavity. We report a rare case of lingual nerve schwannoma in a 16-year-old girl with complaint of right-side submandibular swelling for last 4-5 years. A diagnosis was established based on computed tomography (CT scan) and fine needle aspiration cytology (FNAC). CT scan showed tumor involving right submandibular region and superiorly reaching up to parapharyngeal space without any intraoral swelling. She underwent excision under general anesthesia (transcervical approach) without any complication. Per operatively, the tumor was found eccentrically placed with relation to the lingual nerve and lingual nerve fibers were splayed over the tumor. The final histopathological results confirmed the diagnosis of schwannoma.

Extracranial Head and Neck Schwannomas: A Single Centre Retrospective Experience of 97 Cases.

Introduction: Schwannomas are rare benign neurogenic tumours. About 25-45% of extracranial schwannomas are found in the head and neck region. In the head and neck, they can arise from various cranial, peripheral and autonomic nerves. Due to this, they have varied clinical presentations. Material and Methods: This retrospective cohort includes 97 patients diagnosed with extra cranial head and neck schwannoma, and operated in the Otolaryngology and Head & Neck Surgery department, from 2013 to 2022. The parameters observed were the age and gender distribution, location, nerve of origin, size, pressure symptoms, cranial palsies, post-operative symptoms, recurrence and complications. The data were collected from the institute's electronic records. Results: The median age of the study population was 36 years; among them, 51 were men and 46 were women. The most common tumour location was parapharynx. The patients had varied head and neck symptoms, of which 23.7% had nerve paresis at presentation. Transcervical surgical approaches was most used. New onset cranial nerve paresis immediately post-surgery was noted in 22.7%. Recurrence was noted in 2% of cases. Conclusions: Extra cranial schwannomas are uncommon neoplasms and have varied presentations. Comprehensive evaluation with appropriate imaging should be done in all cases. Though benign, patients can present with nerve paresis. Recurrence is uncommon after complete resection.

Schwannoma of Ansa-Cervicalis: A Rare Location for Schwannoma.

Schwannomas are rare neoplasms that originate from the nervous system. We describe a case of schwannoma of the ansa-cervicalis in a patient where preoperative imaging is suggestive of glomus caroticum tumor. A 44-year-old man presented to the surgical oncology department with a recurrent anterior triangle neck swelling. Magnatic resonance imaging (MRI) demonstrated right enhancing soft tissue mass at the carotid bifurcation consistent with glomus tumor. Intraoperatively, the lesion was found abuting the bifurcatuion and arising from the right ansa-cervicalis. Histopathology evaluation revealed schwannoma. Schwannoma of the ansa-cervicalis is extremely rare. Very few cases have been reported in the literature. Making the preoperative diagnosis is difficult. Preoperative imaging is necessary to rule out other causes of neck masses such as thyroid lesions, lymphadenopathy, and carotid body tumor. Verocay bodies were noted on histology. Schwannoma of cervical region can have origin from any nerve. Any Neurologic post-operative deficit depends on the nerve of origin and the precision of the surgery performed.

A complete facet resection and cervical pedicle screw placement enhances both gross total resection and motion preservation for the cervical spinal dumbbell tumor.

OBJECTIVE: To describe single-index-level fusion surgery using a cervical pedicle screw (CPS) after the complete facet resection of spinal dumbbell tumors and to compare it with partial facet resection without fusion. METHODS: We retrospectively reviewed patients who underwent surgery for dumbbell-shaped cervical spine tumors. They were categorized into the fused group (complete facet resection with fusion using CPS) and the unfused group (partial facet resection without fusion). We compared demographics, tumor characteristics, resection rates (gross total, subtotal, or partial), and regrowth rates between the groups. Complete facet resection was performed for maximal tumor removal. In the fused group, single-index-level fusion was achieved using CPS. Despite tumor-associated erosion of the index vertebra's pedicle and/or lateral mass, the CPS was directly inserted into the vertebral body through an imaginary virtual pedicle without a lateral mass or pedicle purchase. RESULTS: A total of 34 patients underwent surgery for dumbbell-shaped cervical tumors; half were classified into each group. There were no significant differences in demographic or tumor characteristics, including Asazuma classification, or histological diagnosis (P > 0.05). However, the gross total resection rate was significantly higher in the fused group (16/17, 94.1% vs 9/17, 52.9%; P-value = 0.011). Tumor recurrence was observed in three (17.6%) patients in the unfused group; no recurrence (0%) occurred in the fused group. CONCLUSION: Complete facet resection with fusion using CPS significantly increased the gross total tumor removal rate, compared with partial resection without fusion. Therefore, CPS improved fusion surgery for maximal motion preservation, resulting in single-level fusion surgery.

Spinal Schwannoma Classification Based on the Presumed Origin With Preoperative Magnetic Resonance Images.

OBJECTIVE: Classification guides the surgical approach and predicts prognosis. However, existing classifications of spinal schwannomas often result in a high 'unclassified' rate. Here, we aim to develop a new comprehensive classification for spinal schwannomas based on their presumed origin. We compared the new classification with the existing classifications regarding the rate of 'unclassified'. Finally, we assessed the surgical strategies, outcomes, and complications according to each type of the new classification. METHODS: A new classification with 9 types was created by analyzing the anatomy of spinal nerves and the origin of significant tumor portions and cystic components in preoperative magnetic resonance images. A total of 482 patients with spinal schwannomas were analyzed to compare our new classification with the existing classifications. We defined 'unclassified' as the inability to classify a patient with spinal schwannoma using the classification criteria. Surgical approaches and outcomes were also aligned with our new classification. RESULTS: Our classification uniquely reported no 'unclassified' cases, indicating full applicability. Also, the classification has demonstrated usefulness in predicting the surgical outcome with the approach planned. Gross total removal rates reached 88.0% overall, with type 1 and type 2 tumors at 95.3% and 96.0% respectively. The approach varied with tumor type, with laminectomy predominantly used for types 1, 2, and 9, and facetectomy with posterior fixation used for type 3 tumors. CONCLUSION: The new classification for spinal schwannomas based on presumed origin is applicable to all spinal schwannomas. It could help plan a surgical approach and predict its outcome, compared with existing classifications.

Combined Intrathoracic and Intraspinal Approach to a Neurogenic Dumbbell Tumour.

A neurogenic dumbbell tumour is a rare occurrence in which the tumour has an extension through an intervertebral foramen, acquiring an hourglass shape. Surgical strategies to resect these tumours are rapidly evolving, and there is no definite consensus on the approach, stages, and plan of surgery. Here, we present a case report on a dumbbell tumour that was successfully resected via laminectomy and video-assisted thoracoscopic surgery (VATS) approach. A 53-year-old lady had an incidental finding of a mediastinal mass from chest radiography. Computed tomography (CT) and magnetic resonance imaging (MRI) studies showed a neurogenic mass with extension into the posterior mediastinum via the T1/2 neural foramina. A multi-disciplinary operation was planned for the patient, starting with neurosurgery resecting the intraspinal portion via laminectomy. The posterior mediastinal portion of the mass was resected via the right VATS approach and was successfully resected entirely. Her operation was complicated with a cerebrospinal fluid (CSF) leakage, requiring a revisit surgery. She was subsequently discharged well. Histopathology examination of the resected mass confirmed the diagnosis of schwannoma. Surgical resection of a dumbbell tumour is challenging because it involves both the thoracic and neurosurgical fields. There is currently no consensus on the best way to approach a tumour. Multiple articles have discussed various approaches, such as single-stage versus two-stage surgery, VATS versus open incisions, and the plan or sequence of the surgery. Dumbbell tumours need to be assessed on a case-by-case basis, and a multidisciplinary approach involving both neurosurgery and cardiothoracic surgery in deciding the best surgical approach could ensure a successful resection.

Atypical Presentation and Postoperative Management of Vagal Nerve Tumors.

OBJECTIVES: Tumors involving the vagus nerve are often clinically silent. We offer a case series with different clinical presentations and distinctive post-surgical sequelae that highlight some of the challenges associated with managing cervical vagal nerve tumors. METHODS: Single-institution, retrospective review of patients with tumors involving the vagus nerve. We describe clinical presentations and postoperative sequelae of five patients who underwent surgical management of vagal nerve pathology with atypical presentation or subsequent clinical course. RESULTS: Here, we present five patients treated at our institution for vagal tumors. In four of the five patients, the presenting symptoms resolved after surgery. Two patients presented with intractable neurogenic cough, and another two presented with autonomic symptoms, one with syncope/palpitations and the other with intractable sweating. The final patient presented with a rapidly enlarging vagal paraganglioma and developed intractable cough after resection. We present two patients with novel approach to vagal paragangliomas that underwent ligation of feeding blood supply without removing the tumor, resulting in resolution of an intractable cough in one patient and resolution of severe nighttime sweating in the other. CONCLUSION: Management of tumors associated with the cervical vagus nerve that present with symptoms or rapid growth poses a clinical dilemma. Consideration of the tumor origin with either enucleation of schwannomas or ligation of feeding vessels may preserve function while addressing the presenting symptoms.

Posterior location of the facial nerve on vestibular schwannoma: Report of a rare case and a literature review.

Background: Posterior location of the facial nerve in relation to vestibular schwannoma (VS) is extremely rare. Case Description: An elderly man presented with the right cerebellopontine angle (CPA) syndrome. Magnetic resonance imaging showed the partly cystic and partly solid right CPA lesion extending to the internal auditory meatus. Seventh nerve monitoring showed the facial nerve on the posterior surface of the tumor. At surgery, the facial nerve was seen on the posterior surface of the tumor under the microscope. Partial excision of the tumor was done with preservation of the facial nerve both anatomically and electrophysiologically. Conclusion: The posterior location of the facial nerve should be anticipated in all patients with VS. The surgical strategy must be altered appropriately to preserve the facial nerve.