Cases of Mixed Schwannoma-Meningioma With and Without Neurofibromatosis 2 with Emphasis on Tumorigenesis

Concurrent occurrence of schwannoma and meningiomas are rare, and are found especially in association with neurofibromatosis type 2 (NF2). Occurrence of mixed tumor without the aforementioned conditions is extremely rare. We present three cases of mixed tumor in different locations, including two with NF2 and one without NF2. We analyse the relationship of mixed tumor with NF2 and its clinical implications. Presence of mixed schwannoma-meningioma should prompt screening for NF2. Thus aids in early diagnosis of unsuspected NF2 cases. We observed that irrespective of different locations, cases with NF2 showed frequent recurrence of schwannoma as compared to case who did not fit in the existing clinical criteria for NF2. Collision tumor and thereby NF2 mutations indicates the prognosis and recurrence of the tumor, thereby guides in deciding the management.

Physiotherapy Rehabilitation Following Acoustic Neuroma Resection in a Patient With Cerebellopontine Angle Tumour: A Case Report

Acoustic neuroma excision in patients with cerebellopontine angle (CPA) tumours offers particular rehabilitation problems due to the complicated architecture of the cerebellum and brainstem tissues involved. CPA tumours (acoustic neuromas) are slow-growing tumours that arise from the vestibulocochlear nerve. Surgical excision of these tumours can cause neurological abnormalities that compromise motor coordination, balance, and facial nerve function. The case study emphasises the importance of a comprehensive physiotherapeutic approach in rehabilitating a patient following acoustic neuroma excision, with a focus on particular CPA tumour deficits. The rehabilitation programme focuses on improving functional outcomes through balance, proprioception, and vestibular rehabilitation that is customised to the demands and deficiencies of the patient. Our comprehensive approach seeks to improve patients' quality of life, promote neurological healing, and support easy reintegration into normal activities following CPA tumour surgery.

Excision of Greater Superficial Petrosal Nerve Schwannoma Via a Pure Endoscopic Endonasal Approach

Greater superficial petrosal nerve (GSPN) schwannomas are an exceedingly rare nerve sheath tumor. The current literature search was conducted using Medline and Embase database by key search terms. Only 31 cases have been reported in the literature so far. Facial palsy, hearing loss, and xerophthalmia accounted for 48.4% (15), 41.9% (13), and 29% (9) of all cases, respectively. The middle cranial fossa approach was used in all previous reports. A retrospective review of 2 GSPN schwannomas patients treated by endoscopic endonasal approach (EEA) in our center was collected. Clinical records, including clinical features, pre- and postoperative images, surgery, and follow-up information, were reviewed. In all cases, clinical features including facial numbness and headache were found, with tinnitus in case 1, hearing loss, xerophthalmia in case 2. Imaging studies showed a solid mass that originated in the anterior of the petrous bone. Two patients were treated by EEA. Furthermore, no recurrence was found during the follow-up period (15-29 months) in both of the 2 cases after the operation. Complete resection of GSPN schwannomas can be achieved via the pure EEA. Endoscopic endonasal approach for radical removal of tumors is safe and feasible.

[Minimally invasive removal of dumbbell shaped schwannomas with transforaminal lumbar fusion: a retrospective study with a minimum 3-year follow-up]

Currently, there are no standards in surgical treatment of dumbbell-shaped tumors of lumbo-foraminal region.

OBJECTIVE

To evaluate the effectiveness and long-term results of minimally invasive resection of dumbbell-shaped lumbar schwannomas Eden type 2 and 3 combined with transforaminal lumbar interbody fusion and transpedicular stabilization.

MATERIAL AND METHODS

A retrospective study included 13 patients (8 men and 5 women) with lumbar dumbbell tumors Eden type 2 and 3 who underwent minimally invasive facetectomy through posterolateral anatomical corridor, microsurgical tumor resection and MI TLIF. We analyzed intraoperative parameters, neurological functions (ASIA scale), clinical characteristics (ODI, SF-36), and complications. Resection quality and area of the multifidus muscle were assessed according to MRI data. All patients were followed-up throughout at least 3-year.

RESULTS

Surgery time was 147 min, blood loss - 118 ml, hospital-stay - 7 days. Clinical parameters significantly improved in the follow-up period: ODI score decreased from 72 to 12 (p=0.004), SF-36 PCS increased from 26.24 to 48.51 (p=0.006) and MCS score increased from 29.13 to 53.68 (p=0.002). According to MRI data, no tumor recurrences and severe muscle atrophy (>30%) were observed after 3 years in all cases. Superficial wound infection occurred in 1 (7.7%) case. There were normal neurological functions (ASIA type E) in all patients.

CONCLUSION

Minimally invasive facetectomy through posterolateral approach with MI TLIF technology can be used for safe and effective resection of dumbbell-shaped schwannomas Eden type 2 and 3.

A Retrospective Analysis of High Resolution Ultrasound Evaluation of the "Split Fat Sign" in Peripheral Nerve Sheath Tumors

Peripheral nerve sheath tumors (PNST) comprise schwannomas and neurofibromas. The finding of increased adipose tissue around benign PNSTs has been described as the "split fat sign" on magnetic resonance imaging exams, which is suggestive of an intramuscular or intermuscular location of the tumor. However, few studies have described this sign as a salient ultrasound feature of PNSTs. The main purpose of this study was to retrospectively evaluate the presence of increased fatty tissue deposition around benign PNSTs diagnosed by high-resolution ultrasound. In addition, we aimed to corroborate the presence of vascularization around the affected area. A retrospective analysis of ten cases of PNSTs and two cases of post-traumatic neuromas diagnosed by high-resolution ultrasound was performed with a Logiq® P8 ultrasound with a 2-11 MHz multifrequency linear probe L3-12-D (central frequency: 10 MHz). Localized types of neurofibromas and schwannomas in any location were seen as predominantly hypoechoic tumors with an oval or fusiform shape. Exiting and entering nerves (tail sign) were observed in six cases, showing localized lesions both in intermuscular and subcutaneous locations. The presence of increased hyperechoic tissue (the split fat sign) was noted in cases of solitary intermuscular and intramuscular peripheral nerve sheath tumors, mainly the schwannomas. Though small tumors did not demonstrate the tail sign, the increase in adipose tissue and vascularity on US was well demonstrated. In conclusion, the nerve in continuity forms the basis of the ultrasonographic diagnosis of PNSTs. However, high-resolution US can convincingly demonstrate the increased presence of fat in the upper and lower poles as well as circumferentially in intermuscular or intramuscular benign PNSTs.

Neurilemmoma of Tongue in A Young Female: A Case Report

Neurilemmomas are benign, slowly growing tumors originating from Schwann cells in peripheral nerves. The precise cause is unclear. They commonly occur in the head and neck region (25-48% of cases) and rarely in the oral cavity (1%). While lingual schwannomas can develop at any age, they are most frequently seen between the ages of 30 and 60 years. In this case, a 19-year-old female was diagnosed with a lingual schwannoma. She had experienced painless swelling along the left side of her tongue for two years. The examination revealed a non-tender, soft to firm, 2x1 cm lump on the left side of the tongue, covered by healthy mucosa, with no signs of cervical lymph node enlargement. The lesion was completely excised under local anesthesia for histopathological evaluation. Histological examination revealed spindle cells with slender, undulating nuclei in Antoni A and B regions. The prominent nuclear palisading feature typical of schwannomas was evident.

Case report: Combined cervical incision with an intercostal uniportal video-assisted thoracoscopic surgery approach for mediastinal brachial plexus schwannoma

Mediastinal neurogenic tumors primarily originate from the intercostal and sympathetic nerves, whereas schwannomas originating from the brachial plexus are rare. Surgical intervention for such tumors is complex and associated with the risk of postoperative upper limb dysfunction due to their unique anatomical location. In this report, we present the case of a 21-year-old female diagnosed with a mediastinal schwannoma, who underwent a novel surgical approach combining cervical incision and intercostal uniportal video-assisted thoracoscopic surgery (VATS). Our study reviewed the patient's clinical presentation, treatment approach, pathology, and prognosis. The findings of this study demonstrate that the cervical approach, combined with intercostal uniportal VATS, is a feasible surgical method for the removal of mediastinal schwannomas originating from the brachial plexus.

Benign Intrapulmonary Schwannoma With High Uptake on Fluorodeoxyglucose-18 (FDG-18 PET) Presenting as a Pancoast Tumor

A 46-year-old female patient was diagnosed with a rare and benign intrapulmonary schwannoma, a neurogenic tumor that represents approximately 20% of adult mediastinal tumors, with schwannomas being the most common subtype. The patient was initially asymptomatic; however, after a period of four years, the patient presented with bilateral extremity edema, chronic venous stasis, elevated right ventricular systolic pressure, and a slightly enlarged inferior vena cava. These symptoms were caused by the lung tumor compressing intrathoracic structures. This case highlights the need for early evaluation and proper management of neurogenic tumors to avoid serious symptoms and complications. It also emphasizes the importance of vigilant monitoring and prompt surgery to achieve the best outcome for patients with neurogenic tumors.

[New classification and approaches to the treatment of schwannomatosis]

Schwannomatoses is a new classification unit for all the hereditary diseases caused by chromosome 22 damage followed by multiple benign neoplasms of the peripheral and central nervous system. Schwannomatosis occurs as a result of damage to different genes: NF2, SMARCB1, LZRT1, loss of heterozygosity of the long arm of chromosome 22. Nevertheless, clinical manifestations are similar. Molecular diagnostics not only confirms the diagnosis, but also predicts the course of disease. Thus, the most severe clinical manifestations are observed in patients with violation of semantic sequences and reading frame shift in exons 2-13 of the NF2 gene. A more favorable course with less number of tumors is observed in patients with somatic mosaicism. Stereotactic irradiation and surgery are the main treatment options for schwannomatosis. However, there is evidence of effective targeted therapy with bevacizumab (inhibitor of vascular endothelial growth factor). Bevacizumab is used in patients with bilateral vestibular schwannomas and high risk of hearing loss, as well as for intramedullary tumor growth control.

Lung schwannomas, an unusual entity: A series of five cases

Schwannomas are benign slow-growing tumours arising from the Schwann cells of the nerve sheath. They may arise anywhere in the course of the nerves in the body. The clinical presentations are non-specific, and when present in rare locations such as lungs, the diagnosis becomes difficult. The present case series describes the clinical presentation and diagnosis of five cases of lung schwannoma. The diagnosis was mainly assisted by the immuno-histochemical examination comprising markers such as S-100, Calretinin, CD34, CD56, Desmin, and EMA. A definitive diagnosis of benign nerve tumours in such rare locations may help in better pre-operative assessment and surgery for complete recovery of the patients.

Tumors Involving the Infratemporal Fossa: A Systematic Review of Clinical Characteristics and Treatment Outcomes

BACKGROUND

Infratemporal fossa (ITF) tumors represent various pathologies and are seldom described in the literature, reflecting their rarity. Here we review the literature on tumors invading ITF and describe patient characteristics, treatment strategies, and clinical outcomes.

METHODS

Relevant articles were retrieved from PubMed, Scopus, and Cochrane. A systematic review and meta-analysis were conducted on the clinical presentation, treatment protocols, and clinical outcomes.

RESULT

A total of 27 articles containing 106 patients with ITF tumors (median tumor size: 24.3 cm³ [interquartile range, 15.2-42 cm³]) were included (median age: 46 years [interquartile range, 32-55 years]; 59.4% were males]). Of the confirmed tumor pathology data, schwannomas (n = 24; 26.1%) and meningiomas (n = 13; 14.1%) were the most common tumors. Facial hypoesthesia (n = 22; 18.5%), auricular/preauricular pain (n = 20; 16.8%), and headaches (n = 11; 9.2%) were the most common presenting symptoms. Of patients who had surgical resection (n = 97; 95.1%), 70 (73.7%) had transcranial surgery (TCS) and 25 (26.3%) had endoscopic endonasal surgery (EES). Among available details on the extent of resection (n = 84), gross-total resection (GTR) was achieved in 62 (73.8%), and 5 (6.0%) had biopsy only. Thirty-five (33.0%) patients had postoperative complications. Among cases with available data on reconstruction techniques (n = 8), four (50%) had adipofascial antero-lateral thigh flap, three (37.5%) had latissimus dorsi free flap, and one (12.5%) had antero-lateral thigh flap. Fourteen (13.2%) patients had adjuvant chemotherapy, and sixteen (15.1%) had adjuvant radiotherapy. During a median follow-up time of 28 months (IQR, 12.25-45.75 months), 15 (14.2%) patients had recurrences, and 18 (17.0%) patients died. The median overall survival (OS) time was 36 months (95% confidence interval: 29-41 months), and the 5-year progression-free survival (PFS) rate was 61%.

CONCLUSION

Various tumor types with different biological characteristics invade the ITF. The present study describes patient demographics, clinical presentation, management, and outcomes. Depending on the tumor type and patient condition, patient-tailored management is recommended to optimize treatment outcomes.

Quantitative Chemical Exchange Saturation Transfer Imaging of Amide Proton Transfer Differentiates between Cerebellopontine Angle Schwannoma and Meningioma: Preliminary Results

Vestibular schwannomas are the most common tumor at the common cerebellopontine angle, followed by meningiomas. Differentiation of these tumors is critical because of the different surgical approaches required for treatment. Recent studies have demonstrated the utility of amide proton transfer (APT)-chemical exchange saturation transfer (CEST) imaging in evaluating malignant brain tumors. However, APT imaging has not been applied in benign tumors. Here, we explored the potential of APT in differentiating between schwannomas and meningiomas at the cerebellopontine angle. We retrospectively evaluated nine patients with schwannoma and nine patients with meningioma who underwent APT-CEST MRI from November 2020 to April 2022 pre-operation. All 18 tumors were histologically diagnosed. There was a significant difference in magnetization transfer ratio asymmetry (MTR_asym) values (0.033 ± 0.012 vs. 0.021 ± 0.004; p = 0.007) between the schwannoma and meningioma groups. Receiver operative curve analysis showed that MTR_asym values clearly differentiated between the schwannoma and meningioma groups. At an MTR_asym value threshold of 0.024, the diagnostic sensitivity, specificity, positive predictive value, and negative predictive values for MTR_asym were 88.9%, 77.8%, 80.0%, and 87.5%, respectively. Our results demonstrated the ability of MTR_asym values on APT-CEST imaging to discriminate patients with schwannomas from patients with meningiomas.

MR diffusion and dynamic-contrast enhanced imaging to distinguish meningioma, paraganglioma, and schwannoma in the cerebellopontine angle and jugular foramen

BACKGROUND AND PURPOSE

Differentiation of meningiomas, paragangliomas, and schwannomas in the cerebellopontine angle and jugular foramen remains challenging when conventional MRI findings are inconclusive. This study aimed to assess the clinical utility of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced MRI (DCE-MRI) findings for tumor type differentiation and to identify the most significant diagnostic parameters.

METHODS

This retrospective study included 57 patients with pathologically confirmed meningiomas, paragangliomas, and schwannomas, diagnosed between January 2018 and August 2021. DWI and DCE-MRI were obtained before surgery. The apparent diffusion coefficient (ADC) and DCE-MRI parameters were calculated. The Kruskal-Wallis H test and post hoc test with Bonferroni correction and receiver operating characteristic curve were used for statistical analysis.

RESULTS

There were 20 meningiomas (6 men; 62.3 ± 17.8 years), 23 paragangliomas (3 men; 51.6 ± 17.0 years), and 14 schwannomas (7 men; 37.7 ± 20.0 years). V_p showed a significant difference in each comparison (p < .001, <.001, and <.001, respectively), V_e showed significant differences both in meningiomas and paragangliomas, and paragangliomas and schwannomas (p < .001 and .017, respectively), and K_trans showed significant differences both in meningiomas and paragangliomas, and meningiomas and schwannomas (p = .0018 and <.001, respectively), though there was no significant difference in ADC. V_p diagnostic performance values for each pair of tumors were area under the curve of 0.89-1.00, with cutoff values of 0.14-0.27.

CONCLUSION

DCE-MRI can provide promising parameters to differentiate meningiomas, paragangliomas, and schwannomas in the cerebellopontine angle and jugular foramen.

Efficacy of the Suboccipital Paracondylar-Lateral Cervical Approach: The Series of 64 Jugular Foramen Tumors Along With Follow-Up Data

Objective

Complete resection of jugular foramen tumors with minimal cranial nerve complications remains challenging even for skilled neurosurgeons. Here, we introduce a modified paracondylar approach, named the suboccipital paracondylar-lateral cervical (SPCLC) approach for this purpose. We also share the follow-up data of our series and discuss the advantages and limitations of this modified paracondylar approach.

Methods

We included 64 patients with jugular foramen tumors who underwent surgery by the same senior neurosurgeon between November 2011 and August 2020. All patients were treated with the SPCLC approach, which aimed for gross total tumor removal in a single-stage operation. The clinical characteristics, including preoperative and postoperative neurological status, the extent of surgical resection, and follow-up data were retrospectively acquired and evaluated.

Results

There were 48 schwannomas, nine meningiomas, three paragangliomas, one hemangiopericytoma, one chordoma, one endolymphatic sac tumor, and one Langerhans’ cell histiocytosis. The median age of our patients was 43 years (range: 21–77 years). Dysphagia, hoarseness, and tongue deviation were observed in 36, 26, and 28 patients, respectively. Thirty-two patients had hearing function impairments, including hearing loss or tinnitus. Gross total resection was achieved in 59 patients (59/64, 92.2%). Gamma Knife treatment was used to manage residual tumors in five patients. Postoperatively, new-onset or aggravative dysphagia and hoarseness occurred in 26 and 18 cases, respectively. Nine patients developed new-onset facial palsy, and one patient developed new-onset hearing loss. There were no cases of intracranial hematoma, re-operation, tracheostomy, or death. At the latest follow-up, hearing loss and tinnitus had improved in 20 cases (20/32, 62.5%), dysphagia alleviated in 20 cases (20/36, 55.6%), and hoarseness improved in 14 cases (14/26, 53.8%). Over a mean follow-up period of 27.8 ± 19.5 months (range: 3–68 months), tumor recurrence was observed in one patient.

Conclusion

The SPCLC approach, modified from the paracondylar approach, and was less invasive, safe, and efficient for certain jugular foramen tumors. Taking advantage of the anatomic understanding, clear operational vision, and appropriate surgical skills, it is possible to achieve gross total tumor removal and the preservation of neurological function.

Induced phase separation of mutant NF2 imprisons the cGAS-STING machinery to abrogate antitumor immunity

Missense mutations of the tumor suppressor Neurofibromin 2 (NF2/Merlin/schwannomin) result in sporadic to frequent occurrences of tumorigenesis in multiple organs. However, the underlying pathogenicity of NF2-related tumorigenesis remains mostly unknown. Here we found that NF2 facilitated innate immunity by regulating YAP/TAZ-mediated TBK1 inhibition. Unexpectedly, patient-derived individual mutations in the FERM domain of NF2 (NF2m) converted NF2 into a potent suppressor of cGAS-STING signaling. Mechanistically, NF2m gained extreme associations with IRF3 and TBK1 and, upon innate nucleic acid sensing, was directly induced by the activated IRF3 to form cellular condensates, which contained the PP2A complex, to eliminate TBK1 activation. Accordingly, NF2m robustly suppressed STING-initiated antitumor immunity in cancer cell-autonomous and -nonautonomous murine models, and NF2m-IRF3 condensates were evident in human vestibular schwannomas. Our study reports phase separation-mediated quiescence of cGAS-STING signaling by a mutant tumor suppressor and reveals gain-of-function pathogenesis for NF2-related tumors by regulating antitumor immunity.

Scoring systems for differentiating gastrointestinal stromal tumors and schwannomas from leiomyomas in the stomach

There is no practical predictive model for the diagnosis of gastrointestinal stromal tumors (GISTs). To establish a practical predictive model for the diagnosis of subepithelial lesions in the stomach, we reviewed patients with GISTs (n = 89), schwannomas (n = 7), and leiomyomas (n = 28).The tumor was more frequently found along the gastric cardia in the leiomyoma group (57.1%) than in the GIST/schwannoma group (2.1%, P < .01). Contrast enhancement (57.3% vs 0%, P < .01) and intra-tumoral necrosis (34.4% vs 0.0%, P < .01) were more frequently observed in the GIST/schwannoma group than in the leiomyoma group. On endoscopic ultrasonography, 58.3% of GISTs/schwannomas showed uneven echogenicity, whereas the echogenicity was uneven in 21.4% of leiomyomas (P < .01). There were no differences between the tumor color and the presence or absence of ulcer formation, tumor bleeding, irregularity of the tumor margin, cystic spaces, and hyperechoic spots between the 2 groups. Based on these results, we developed a 2-step diagnostic algorithm for GISTs/schwannomas. The first step comprises 1 endoscopic feature: a cardiac or non-cardiac location. Tumors with a cardiac location were judged as leiomyomas and those with a non-cardiac location were judged as GISTs/schwannomas, with 96.9% sensitivity and 57.1% specificity for GIST/schwannoma diagnosis. The second step comprises a combination of endoscopic (non-cardiac location), radiologic (positive contrast enhancement and intra-tumoral necrosis), and endosonographic (uneven echogenicity) features for a total of 4 points. We assigned 1 point to each feature. Tumors with scores of 2 to 4 were judged as GISTs/schwannomas, with 81.3% sensitivity and 92.9% specificity for GIST/schwannoma diagnosis.Our predictive model will be a practical guide for the management of gastric subepithelial lesions.

Diagnostic Dilemma of Retroperitoneal Schwannomas Encountered in a Specialized Gynecology Hospital

BACKGROUND

This study analyzed the potential diagnosis and therapeutic challenges of retroperitoneal schwannoma (RSs) in a specialized gynecology hospital.

METHODS AND MATERIALS

A retrospective review was performed in our hospital from 2000 to 2018. A literature search of RSs was conducted using PubMed database.

RESULTS

45 patients were identified (22 from our hospital and 23 from the literature review). The majority of patients presented asymptomatic (22/45). Among them, 25 cases were misdiagnosed as adnexal cysts, 13 uterine fibroids, 1 ovarian malignancy and 6 pelvic masses. Intraoperative exploration revealed that the masses were located in the retroperitoneal space. The median diameter was 6.2 cm (range 3.0-9.8 cm) in our hospital compared with 9.3 cm (6-15 cm) in literature review. Complete resection was performed in 37 patients and subtotal resection in 8 patients. The pathological results confirmed the diagnosis of benign schwannoma and no recurrence was found in the follow-up data.

CONCLUSION

The preoperative diagnosis of RSs is difficult to make because of its nonspecific characteristics. In a specialized gynecology hospital, it is more important to differentiate the benign and malignant of mass before surgery. Surgical complete resection of tumor is recommended and recurrence is unusual after complete resection.

Outcomes after stereotactic radiosurgery for schwannomas of the oculomotor, trochlear, and abducens nerves

OBJECTIVE

Cranial nerve (CN) schwannomas are intracranial tumors that are commonly managed by stereotactic radiosurgery (SRS). There is a large body of literature supporting the use of SRS for vestibular schwannomas. Schwannomas of the oculomotor nerves (CNs III, IV, and VI) are rare skull base tumors, occurring close to the brainstem and often involving the cavernous sinus. Resection can cause significant morbidity, including loss of nerve function. As for other schwannomas, SRS can be used to manage these tumors, but only a handful of cases have been published so far, often among reports of other uncommon schwannoma locations.

METHODS

The goal of this study was to collect retrospective multicenter data on tumor control, clinical evolution, and morbidity after SRS. This study was performed through the International Radiosurgery Research Foundation. Patients managed with single-session SRS for an oculomotor cranial nerve schwannoma (CN III, IV, or VI) were included. The diagnosis was based on diplopia or ptosis as the main presenting symptom and anatomical location on the trajectory of the presumed cranial nerve of origin, or prior resection confirming diagnosis. Demographic, SRS dose planning, clinical, and imaging data were collected from chart review of the treated patients. Chi-square and Kaplan-Meier analyses were performed.

RESULTS

Seven institutions submitted data for a total of 25 patients. The median follow-up time was 41 months. The median age at the time of treatment was 52 years. There were 11 CN III schwannomas, 11 CN IV schwannomas, and 3 CN VI schwannomas. The median target volume was 0.74 cm3, and the median marginal dose delivered was 12.5 Gy. After SRS, only 2 patients (including the only patient with neurofibromatosis type 2) had continued tumor growth. Crude local control was 92% (23/25), and the 10-year actuarial control was 86%. Diplopia improved in the majority of patients (11/21), and only 3 had worsening following SRS, 2 of whom also had worsened ptosis, both in the context of tumor progression.

CONCLUSIONS

SRS for schwannomas of the oculomotor, trochlear, and abducens nerves is effective and provides tumor control rates similar to those for other cranial nerve schwannomas. SRS allows improvement of diplopia in the majority of patients. SRS should therefore be considered as a first-line treatment option for oculomotor nerve schwannomas.

[Complex treatment of a patient with neurofibromatosis type 2]

Neurofibromatosis type 2, a rare disease, the most characteristic manifestation of which is the presence of bilateral vestibular schwannomas, less often schwannomas of other cranial, spinal and peripheral nerves. Much less frequent are meningiomas (intracranial, including meningiomas of the optic nerves, and spinal), epindymomas and gliomas. As a rule, in one patient several formations occur simultaneously, which creates a certain difficulty in treatment tactics. The authors present a case of type 2 neurofibromatosis in a 22-year-old female patient with multiple schwannomas of spinal roots and an atypical intraventricular meningioma.

Ultrasound Imaging for a Rare Cause of Sciatica: A Schwannoma of the Sciatic Nerve

Sciatica is a common musculoskeletal complaint, but it is rarely attributed to peripheral nerve tumors. Until now, there is little literature reporting sciatica caused by a sciatic schwannoma at the proximal thigh. A 27-year-old male had left posterior proximal thigh pain for more than two years. Compression of the tender point caused numbness radiating to his low back, buttock and leg regions. Due to poor response to conservative treatments, he was referred for an ultrasound examination, which revealed a solid mass on the track of the sciatic nerve. The subsequent magnetic resonance imaging showed a well-defined tumor sized 2.3 × 1.8 × 2.3 cm beside the sciatic nerve, and a schwannoma was confirmed by postsurgical pathology. In conclusion, ultrasound is helpful in differentiating between the various causes of posterior thigh pain, which, in this case, facilitated detection of a sciatic nerve schwannoma and subsequent surgical removal.

Bioactive Phenolic Compounds in the Modulation of Central and Peripheral Nervous System Cancers: Facts and Misdeeds

Efficacious therapies are not available for the cure of both gliomas and glioneuronal tumors, which represent the most numerous and heterogeneous primary cancers of the central nervous system (CNS), and for neoplasms of the peripheral nervous system (PNS), which can be divided into benign tumors, mainly represented by schwannomas and neurofibromas, and malignant tumors of the peripheral nerve sheath (MPNST). Increased cellular oxidative stress and other metabolic aspects have been reported as potential etiologies in the nervous system tumors. Thus polyphenols have been tested as effective natural compounds likely useful for the prevention and therapy of this group of neoplasms, because of their antioxidant and anti-inflammatory activity. However, polyphenols show poor intestinal absorption due to individual intestinal microbiota content, poor bioavailability, and difficulty in passing the blood-brain barrier (BBB). Recently, polymeric nanoparticle-based polyphenol delivery improved their gastrointestinal absorption, their bioavailability, and entry into defined target organs. Herein, we summarize recent findings about the primary polyphenols employed for nervous system tumor prevention and treatment. We describe the limitations of their application in clinical practice and the new strategies aimed at enhancing their bioavailability and targeted delivery.

Multiple heterogeneous tumors in orbit: a case report

Primary orbital tumors are common; clinically common are single tumors in orbit; and cavernous hemangioma is the most common. Multiple tumors in the same orbit are rare, which have homology and heterogeneity. Multiple tumors of homology are multiple textures of a tumor while multiple heterogeneous tumors have two or more textures. Various tumor tissues, heterogeneous multiple orbital tumors are sporadic. Our department admitted one patient in October 2015. A 54-year-old male patient had proptosis growing gradually in his right eye beginning ten years ago, with decreased vision for more than one year. The primary diagnosis of the right eye orbital double-source primary tumor was diagnosed by imaging. The pathological examination after the operation was confirmed as cavernous hemangioma and schwannomas.

Renal hybrid oncocytic/chromophobe tumor associated with multiple schwannomas: Case report and literature review

RATIONALE

Renal hybrid oncocytic/chromophobe tumors (HOCTs) are benign tumors containing a mixture of cells with features of chromophobe renal cell carcinoma (CHRCC) and renal oncocytoma (RO). Sporadic HOCT, which means HOCT occurs in patients without Birt-Hogg-Dubé syndrome (BHDS) or renal oncocytosis, is extremely rare. In this article, we would report a new case of a patient with both sporadic HOCT and multiple Schwannomas, which is even rarer than simplex sporadic HOCT.

PATIENT CONCERNS

A 48-year-old female was noted with multiple left-kidney masses and a history of multiple Schwannomas. She had no complaints of urological symptoms, abdominal pain, and osphyalgia. The vital sign was stable and blood biochemistry test showed normal renal function. Enhanced computed tomography (CT) found multiple lesions occupying parenchyma of the left kidney. The largest one was measured 3.5 × 3.1 × 3.2 cm. It showed apparently enhancement in arterial phase and low-density in venous phase.

DIAGNOSES

The preoperative diagnosis was renal cell carcinomas.

INTERVENTIONS

The masses were removed by laparoscopic partial left nephrectomy.

OUTCOMES

The diagnosis of HOCT was made by histopathology after surgery. No evidence of local recurrence or distant metastasis was noted on imaging after 2-month follow-up.

LESSONS

We searched PubMed for cases of sporadic HOCT and a total of 26 patients were evaluated. Our case was the first one involving sporadic HOCT and multiple Schwannomas. Although rare, sporadic HOCT does exist in patients presented with renal mass. Urological surgeons should be aware of the existence of HOCT when considering masses on kidney due to the different prognosis between HOCT and renal cell carcinoma. Further, a possible genetic relationship between HOCT and Schwannoma may contribute to a common pathogenesis in these 2 tumors.

Spinal epidural capillary hemangioma: A rare case report with a review of literature

Background:

Purely epidural capillary hemangiomas are very rare. There are only 6 such reports.

Case Description:

A 50-year-old male presented with a progressive lower extremity paraparesis. Magnetic resonance imaging demonstrated a purely epidural lesion at the L1-L2 level without any bony involvement. Following an L1-L2 laminectomy for total excision of the lesion, the patient showed significant improvement. The histopathology was consistent with a pure capillary hemangioma.

Conclusion:

The radiological presentation of purely epidural capillary hemangiomas are often similar to those of schwannomas and meningiomas. Surgical confirmation of the pathology, and gross total excision of these lesions is recommended.

Developing an algorithm for cost-effective, clinically judicious management of peripheral nerve tumors

Peripheral nerve tumors such as neurofibromas and schwannomas have become increasingly identified secondary to improved imaging modalities including magnetic resonance neurogram and ultrasound. Given that a majority of these peripheral nerve tumors are benign lesions, it becomes important to determine appropriate management of such asymptomatic masses. We propose a normal cost-effective management paradigm for asymptomatic peripheral nerve neurofibromas and schwannomas that has been paired with economic analyses. Specifically, our management paradigm identifies patients who would benefit from surgery for asymptomatic peripheral nerve tumors, while providing cost-effective recommendations regarding clinical exams and serial imaging for such patients.

Multiple schwannomas synchronously occurring in the porta hepatis, liver, and gallbladder: first case report

BACKGROUND

Schwannomas are mesenchymal neoplasms that arise from Schwann cells with low malignant potential. Schwannomas originating from the porta hepatis or intra-abdominal organs are extremely rare. To our knowledge, multiple schwannomas synchronously occurring in the porta hepatis, liver, and gallbladder have not been reported so far and we first report one in the present case.

CASE SUMMARY

A 31-year-old female was referred to our hospital because of repeated abdomen discomfort, slight abdominal distension, and occasional abdominal pain for seven years. Ultrasound and computed tomography and magnetic resonance cholangiopancreatography found multiple intrahepatic and extrahepatic cystic lesions with the dilation of intrahepatic and extrahepatic bile ducts. By exploratory laparotomy, multiple tumors were found in the porta hepatis, liver, and gallbladder, the biggest one was 11 × 6 cm in size. We completely resected these tumors combined with the left lateral liver lobe, gallbladder, and the invaded left and right hepatic arteries, and then severed vessels were reconstructed. Microscopically, the tumor cells were spindle shaped and palisading arrangement. Atypical cells or signs of malignancy were not found. Immunohistochemical investigation showed the protein S-100 was positive, while SMA, CD34, and CD117 negative. Finally, these tumors were diagnosed as schwannomas in the porta hepatis, liver, and gallbladder. The patient is followed-up for 70 months and has been doing well without any complications.

CONCLUSION

We report the first patient with multiple schwannomas synchronously occurring in the porta hepatis, liver, and gallbladder. Accurate preoperative diagnosis of these tumors is difficult. Due to closely adhering to the surrounding important tissues, complete removal is challenging.

Extracranial schwannoma in the carotid space: A retrospective review of 91 cases

BACKGROUND

Schwannomas of the vagus nerve and cervical sympathetic nerve are rare; hence, only limited information exists regarding their diagnosis and clinical management.

METHODS

We conducted a retrospective review of the clinical features, imaging studies, and treatment results of patients with schwannoma of the vagus nerve and schwannoma of the sympathetic nerve.

RESULTS

Of 91 patients, 91% (n = 83) were preoperatively diagnosed with schwannoma tumors. Using the hyoid bone as an anatomic landmark, the location of the schwannoma of the vagus nerve in the carotid space was significantly different to the location of schwannoma of the sympathetic nerve (p = .003). Although 52 of the 76 patients followed up (68%) had postoperative nerve weaknesses, 13 patients (50%) and 14 patients (53.8%), respectively, fully recovered from schwannoma of the vagus nerve and schwannoma of the sympathetic nerve.

CONCLUSION

In the carotid space, schwannomas of the vagus nerve are usually located below the hyoid bone, whereas schwannomas of the sympathetic nerve more commonly arise from the suprahyoid compartment. Accurate preoperative diagnosis and the intracapsular enucleation surgical approach decreased the incidence of postoperative morbidity. © 2016 Wiley Periodicals, Head Neck 39: 42-47, 2017.

Gamma Knife radiosurgery in the treatment of abducens nerve schwannomas: a retrospective study

OBJECTIVE Of the intracranial schwannomas, those arising from the vestibular nerves are the most common. Abducens nerve (AN) schwannomas are very rare, and there is limited literature on their optimal management. Therapeutic options include surgery and/or stereotactic radiosurgery. The aim of this study was to evaluate the role of Gamma Knife radiosurgery (GKRS) in these sixth cranial nerve (CN) schwannomas. METHODS The authors performed a retrospective analysis of patients who had undergone GKRS for intracranial tumors at their institute in the period from 2003 to 2010. Inclusion criteria were as follows: isolated AN paresis on presentation, a lesion along the course of the sixth CN, and imaging features characteristic of a schwannoma. Patients with other CN deficits and neurofibromatosis Type 2 were excluded. Symptomatic improvement was defined as the resolution of or an improvement in diplopia noted on a subjective basis or as an improvement in lateral eyeball excursion noted objectively on follow-up. A reduction in tumor volume by at least 20%, as noted by comparing the pre- and post-GKRS images, was deemed significant. RESULTS Six patients with a mean age of 37.1 years (range 17-55 years) underwent primary GKRS. There were 2 prepontine cistern, 3 cavernous sinus, and 1 cisterno-cavernous tumor. The mean duration of symptoms was 6.1 months (range 3-12 months). The mean tumor volume was 3.3 cm³ (range 1.5-4.8 cm³). The mean tumor margin radiation dose was 12.5 Gy (range 12-14 Gy), while the median margin dose was 12 Gy (50% isodose line). The median number of isocenters used was 5 (range 4-8). The brainstem received an average 8.35-Gy radiation dosage (range 5.5-11 Gy). The mean follow-up duration was 44.3 months (range 24-78 months). Symptoms remained stable in 1 patient, improved in 3, and resolved in 2 (total improvement 83%). Magnetic resonance imaging at the last follow-up showed a stable tumor size in 3 patients (50%) and a reduction in the other 3. Thus, the tumor control rate achieved was 100%. No new CN deficits were noted. CONCLUSIONS Abducens nerve schwannomas are rare intracranial tumors. They can be cavernous, cisternal, or cisterno-cavernous in location. Excellent tumor control rates and symptomatic improvement can be achieved with GKRS, which appears to be a safe and effective, minimally invasive modality for the treatment of such lesions. Therefore, it is reasonable to consider GKRS as the initial treatment of choice for this rare pathology. Long-term follow-up will be essential for further recommendations.

Schwannomas exhibit distinct size-dependent gene-expression patterns

AIM

Neurofibromatosis type 2 (NF2)-associated vestibular schwannomas have variable size at presentation which presents a unique challenge in NF2 patient management. Therefore, we investigated the molecular signature characteristic of the differences in size for improved individualized precise therapy.

MATERIALS & METHODS

RNA expression analysis was performed on 15 small and 27 large NF2-associated vestibular schwannoma tumors using a microarray analyzing over 47,000 transcripts.

RESULTS

A signature of 11 genes was found to be correlated with NF2 tumor size.

CONCLUSION

We have identified the genetic hallmark that differentiates large NF2-associated tumors from smaller tumors. This is the first time that these genes have been shown to be the hallmark for NF2 tumor size.

Gastric Malignant Peripheral Nerve Sheath Tumor: A Case Report

Gastric malignant peripheral nerve sheath tumors (MPNSTs) are sarcomas arising within a peripheral nerve. Gastric MPNSTs are extremely rare with only a few cases. We herein describe the case of a 48-year-old man with a gastric MPNST for the first time in Korea, which was diagnosed histopathologically after surgery. The patient underwent curative subtotal gastrectomy with D1+ lymph node dissection and Billroth-II reconstruction. The postoperative recovery was uneventful, and he has had no recurrence until now. The ideal adjuvant treatment protocol is yet to be decided due to the relatively limited number of cases of these tumors previously reported.

Ancient schwannoma of the orbit

The ancient schwannoma is a rare variant of a neurilemoma with a course typical of a slow-growing benign neoplasm. Histologically, it can be confused with a malignant mesenchymal tumor because of increased cellularity, nuclear pleomorphism, and hyperchromatism. Despite the degree of nuclear atypia, mitotic figures are absent. We describe the clinical and histopathologic features of an ancient schwannoma of the orbit. A need for early removal of such tumors is recommended to prevent complications.

Intracranial nonvestibular neurinomas: Young neurosurgeons' experience

BACKGROUND AND OBJECTIVES

Neurinoma arising from other than nonvestibular cranial nerves is less prevalent. Here we present our experiences regarding the clinical profile, investigations, microneurosurgical management, and the outcome of nonvestibular cranial nerve neurinomas.

MATERIALS AND METHODS

From January 2005 to December 2011, the recorded documents of operated nonvestibular intracranial neurinomas were retrospectively studied for clinical profile, investigations, microneurosurgical management, complications, follow-up, and outcomes.

RESULTS

The average follow-up was 24.5 months. Total number of cases was 30, with age ranging from 9 to 60 years. Sixteen cases were males and 14 were females. Nonvestibular cranial nerve schwannomas most commonly originated from trigeminal nerve followed by glossopharyngeal+/vagus nerve. There were three abducent nerve schwannomas that are very rare. There was no trochlear nerve schwannoma. Two glossopharyngeal+/vagus nerve schwannomas extended into the neck through jugular foramen and one extended into the upper cervical spinal canal. Involved nerve dysfunction was a common clinical feature except in trigeminal neurinomas where facial pain was a common feature. Aiming for no new neurodeficit, total resection of the tumor was done in 24 cases, and near-total resection or gross total resection or subtotal resection was done in 6 cases. Preoperative symptoms improved or disappeared in 25 cases. New persistent deficit occurred in 3 cases. Two patients died postoperatively. There was no recurrence of tumor till the last follow-up.

CONCLUSION

Nonvestibular schwannomas are far less common, but curable benign lesions. Surgical approach to the skull base and craniovertebral junction is a often complex and lengthy procedure associated with chances of significant morbidity. But early diagnosis, proper investigations, and evaluation, along with appropriate decision making and surgical planning with microsurgical techniques are the essential factors that can result in optimum outcome.

LIM domain kinases as potential therapeutic targets for neurofibromatosis type 2

Neurofibromatosis type 2 (NF2) is caused by mutations in the NF2 gene that encodes a tumor-suppressor protein called merlin. NF2 is characterized by formation of multiple schwannomas, meningiomas and ependymomas. Merlin loss-of-function is associated with increased activity of Rac and p21-activated kinases (PAKs) and deregulation of cytoskeletal organization. LIM domain kinases (LIMK1 and 2) are substrate for Cdc42/Rac-PAK and modulate actin dynamics by phosphorylating cofilin at serine-3. This modification inactivates the actin severing and depolymerizing activity of cofilin. LIMKs also translocate into the nucleus and regulate cell cycle progression. Significantly, LIMKs are overexpressed in several tumor types, including skin, breast, lung, liver and prostate. Here we report that mouse Schwann cells (MSCs) in which merlin function is lost as a result of Nf2 exon2 deletion (Nf2(ΔEx2)) exhibited increased levels of LIMK1, LIMK2 and active phospho-Thr508/505-LIMK1/2, as well as phospho-Ser3-cofilin, compared with wild-type normal MSCs. Similarly, levels of LIMK1 and 2 total protein and active phosphorylated forms were elevated in human vestibular schwannomas compared with normal human Schwann cells (SCs). Reintroduction of wild-type NF2 into Nf2(ΔEx2) MSC reduced LIMK1 and LIMK2 levels. We show that pharmacological inhibition of LIMK with BMS-5 decreased the viability of Nf2(ΔEx2) MSCs in a dose-dependent manner, but did not affect viability of control MSCs. Similarly, LIMK knockdown decreased viability of Nf2(ΔEx2) MSCs. The decreased viability of Nf2(ΔEx2) MSCs was not due to caspase-dependent or -independent apoptosis, but rather due to inhibition of cell cycle progression as evidenced by accumulation of cells in G2/M phase. Inhibition of LIMKs arrests cells in early mitosis by decreasing aurora A activation. Our results suggest that LIMKs are potential drug targets for NF2 and tumors associated with merlin deficiency.

A case of schwannoma in kidney

Schwannoma is a tumor derived from the Schwann cell of the peripheral nerve sheath and frequently occurs in the head, neck, or extremities. Schwannoma is extremely rare in the kidney, which has nonspecific symptoms and limited radiologic features, and is often diagnosed histologically after surgery. In this study, we report a case of a left renal schwannoma which was misdiagnosed as renal cell carcinoma and confirmed after the surgical removal of the affected kidney.

Schwannoma originating in lateral recess of the fourth ventricle

Intracranial schwannomas most commonly occur in relation to vestibular nerves followed by trigeminal nerves. Authors describe a very unusual case of schwannomas originating in lateral recess of the fourth ventricle. Tumor was completely excised micro-surgically via midline suboccipital craniectomy and C1 laminectomy. Dissection of the surgical specimen revealed that the tumor was completely free from surrounding structures and just hanging in the fourth ventricle. It was not attached to any cranial nerves, brain parenchyma, and blood vessel or to the dura mater. Histopathological examination confirmed the diagnosis of schwannoma. To our knowledge, no such case has been reported so far from this extremely rare location. Relevant literature is reviewed and hypothesis for ectopic location of these tumors has been highlighted.

The puzzling olfactory groove schwannoma: a systematic review

We systematically reviewed the literature concerning the anterior cranial fossa schwannomas to understand their pathogenesis, determine their origin, and standardize the terminology. We performed a MEDLINE, EMBASE, and Science Citation Index Expanded search of the literature; age, gender, clinical presentation, presence or absence of hyposmia, radiological features, and apparent origin were analyzed and tabulated. Cases in a context of neurofibromatosis and nasal schwannomas with intracranial extension were not included. Age varied between 14 and 63 years (mean = 30.9). There were 22 male and 11 female patients. The clinical presentation included seizures (n = 15), headache (n = 16), visual deficits (n = 7), cognitive disturbances (n = 3), and rhinorrhea (n = 1). Hyposmia was present in 14 cases, absent in 13 cases (39.3%), and unreported in five. Homogeneous and heterogeneous contrast enhancement was observed in 14 and 15 cases, respectively. The region of the olfactory groove was the probable site in 96.5%. Olfactory tract could be identified in 39.3%. The most probable origin is the meningeal branches of trigeminal nerve or anterior ethmoidal nerves. Thus, olfactory groove schwannoma would better describe its origin and pathogenesis and should be the term preferentially used to name it.

Pediatric spinal schwannomas: An institutional study

OBJECTIVE

The objective was to analyze the demography, clinical presentation, and management of spinal intradural schwannomas in pediatric population.

MATERIALS AND METHODS

This retrospective study includes 21 pediatric patients (under 18 years of age) who underwent surgery for spinal intradural schwannomas from January 1998 to April 2008. The medical records were reviewed retrospectively and the information regarding clinical presentation, tumor location, operative findings, and postoperative status and functional outcome were analyzed.

RESULTS

A total of 21 patients (14 females and 7 males) were operated for spinal schwannomas. Six patients had associated neurofibromatosis (five were NF I and one was NF II) at presentation. The most common presenting symptom was progressive myelopathy (86%). The tumor location was either cervical or dorsal in 18 cases. All patients underwent surgery. Gross total excision was achieved in 20 cases. The median follow-up was 38 months. All the patients had neurological improvement in both power and bladder symptoms.

CONCLUSION

Pediatric spinal neurofibromas/schwannomas are an uncommon but completely treatable group of tumors. Complete surgical excision gives excellent outcome.

Extramedullary intradural spinal tumors: a review of modern diagnostic and treatment options and a report of a series

Extramedullary intradural spinal tumors are rare. Less than 15% of all central nervous system (CNS) tumors are spinal. Ninety percent of these patients are older than 20 years. Most of spinal tumors are extradural (50-55%) whereas 40-45% are intradural. Furthermore, 5% are intramedullary and 40% are extramedullary. Most common are Schwannomas (29%), followed by meningiomas (25%) and gliomas (22%). These tumors produce pain syndromes, a variety of neurological symptoms- motor, sensory, sphincter or a combination of thereof. All spinal levels may be involved. The diagnostics includes magnetic resonance imaging (MRI) including contrast enhancement, computerizing tomography (CT) scanning (bone windows with reconstruction) and possibly CT myelograms. Preferred treatment is the microsurgical radical resection. Perioperative mortality is very low as is serious morbidity.We herein discuss various aspects of presenting symptomatology, diagnostics, preoperative planning and tactics, surgical treatment and complications. In addition, we include our own retrospective experience with 14 patients treated over the 5.5 years time interval.

Extrahepatic biliary schwannomas: a case report

Benign schwannomas arise in neural crest-derived Schwann cells. They can occur almost anywhere in the body, but their most common locations are the central nervous system, extremities, neck, mediastinum, and retroperitoneum. Schwannomas occurring in the biliary tract are extremely rare and mostly present with obstructive jaundice. We recently experienced a case of extrahepatic biliary schwannomas in a 64-yr-old female patient who presented with intra- and extrahepatic bile duct and gallbladder stones during a screening program. To the best of our knowledge, extrahepatic biliary schwannomas associated with bile duct stones have not been reported previously in the literature.