Robot-assisted minimally invasive bronchial resection with primary anastomosis for schwannoma arising from left main bronchus: a case report

Background

Tracheobronchial schwannomas are extremely rare, which account for lower than 0.2% in all pulmonary tumors. In large part because of the rarity and insufficient reported clinical details, tracheobronchial schwannoma lacks guidelines or expert consensus for diagnosis and treatment, and the delay in diagnosis can range from months to years. The main treatment option is surgery. Endoscopic intervention can also be selected. An increasing number of thoracic surgery cases were performed on the robotic platforms in recent years. With their assistance, surgeons can accomplish the high technique required surgical procedures with ease.

Case Description

In this case, a 48-year-old female had a history of shortness of breath for more than 1 year. The chest computed tomography (CT) and bronchoscopy examination revealed a new growth of nodule in the left main bronchus. The nodule was considered a schwannoma by transbronchial biopsy, which was removed by robot-assisted bronchial resection with primary anastomosis. The application of Da Vinci Si robotic surgical system benefited the process of this surgery. Pathology and immunohistochemistry results confirmed the diagnosis of schwannomas. The patient tolerated the treatment without any complications. No sign of recurrence was discovered at present, 6 months after the intervention.

Conclusions

We reported the first sleeve resection for bronchial schwannoma using Da Vinci robotic surgical system. The clinical details of tracheobronchial schwannoma should be revealed more specifically to achieve more systematic diagnosis and treatment.

Notch appearance as a novel radiological predictor of transient expansion and good outcome of expanding schwannoma after radiotherapy

OBJECTIVES

Schwannoma expansion after radiotherapy has not been well-studied despite the clinical importance of distinguishing transient increase from permanent expansion. Thus, this study aimed to identify the underlying mechanism and novel radiological predictors of schwannoma expansion after radiotherapy.

MATERIALS & METHODS

We retrospectively examined the therapeutic effects of radiotherapy on schwannomas and magnetic resonance images of 43 patients with vestibular schwannomas who underwent stereotactic radiotherapy or radiosurgery at our facility between June 1, 2012 and September 1, 2018. Based on the size change pattern, the treated tumors were classified into six groups, including transient-expansion and consistent-increase groups. The apparent diffusion coefficient (ADC) ratio and appearance of any notch were included as evaluation items based on our hypothesis that transient expansion is due to edema with increased extracellular free water. A log-rank test was performed to evaluate the relationship between the local control rate and radiological signs.

RESULTS

The mean overall 5-year local control rate was 90%, and the median follow-up period was 62 (24-87) months. Approximately 28% of the tumors showed transient expansion; all ADC ratios synchronized with size change, and 75% showed a new notch appearance. Approximately 9% of tumors showed consistent increase, with no notch on the outline. The log-rank test revealed a difference in the local control rate with or without notch appearance in expanding irradiated schwannomas. All tumors with notch appearance showed a significant regression 5 years after radiation.

CONCLUSIONS

New notch appearance on the outline could indicate favorable long-term outcomes of expanding schwannomas post-treatment.

CLINICAL RELEVANCE STATEMENT

Notch appearance can help differentiate a transient schwannoma from a real tumor expansion, and it is a novel predictor of better outcomes of expanding schwannomas after radiotherapy.

Hypoglossal Nerve Palsy Misdiagnosed as Tongue Tumor: A Rare Case of Calcified Hypoglossal Schwannoma

The authors hereby present a case of a calcified schwannoma of the hypoglossal nerve, which led to hypoglossal nerve palsy initially misinterpreted as a tongue tumor. This paper reviews the presentation of schwannoma of the hypoglossal nerve and offers a novel perspective on this rare condition. Diagnostic pitfalls and the diagnostic-therapeutic value are also discussed.

Conservative or surgical management of orbital schwannomas: a population-based case series

INTRODUCTION

Orbital schwannomas (OS) are rare occurrences with no more than 500 cases reported in the literature. The tumor's potential to compromise the delicate neuro-ophthalmic structures within the orbit prompts surgical removal. Tumor removal is performed by ophthalmologists, often requiring a multidisciplinary surgical approach. The literature contains a very limited number of cases managed non-surgically. However, the inherent risks of orbital surgery warrant a comparison of the outcomes of conservative and surgical management strategies.

AIMS

To review the national Swedish experience with the management of orbital schwannomas.

METHODS

The study center is the primary Swedish referral center for the multidisciplinary management of orbital tumors, including schwannomas. During the period of 2005 to 2021, 16 patients with an OS diagnosis were managed at the center.

RESULTS

Four patients initially underwent surgery where gross total resection (GTR) was achieved in three (75%) and subtotal resection (STR) in one (25%) case. The remaining 12 patients, who had a low risk of neuro-ophthalmic impairment, were managed conservatively with radiological and clinical examinations at regular intervals. After an average follow-up of 17 months, surgery was performed in three of these cases (25%). No recurrences or tumor growths were detected on radiological follow-ups (mean 50 months), and all patients experienced postoperative improvement at clinical follow-up (mean 65 months). The remainder of the conservatively treated patients (n=9) experienced no clinical progression (mean 30 months). A slight radiological tumor progression was detected in one patient after 17 months.

CONCLUSION

There were no differences in long-term outcome between patients who had been managed with early surgery and those operated later after an initially conservative management. Conservatively treated patients had minimal to no symptoms and remained clinically stable throughout the follow-up period. Based on these findings, conservative management may successfully be adopted in cases with mild symptoms, no signs of compressive optic neuropathy and low risk of neuro-ophthalmic impairment. Conversion to surgical management is indicated upon clinical deterioration or tumor growth. Based on the findings of this study a decision tree for the management of orbital schwannomas is suggested.

Solitary intraosseous neurofibroma in the mandible mimicking a cystic lesion: A case report and review of literature

BACKGROUND

Neurofibromas are benign tumors of a neurogenic origin. If these tumors occur without any other signs of neurofibromatosis, they are classified as isolated neurofibromas. Neurofibromas in the oral cavity mostly occur within soft tissues, indicating that solitary intraosseous neurofibromas in the mandible are rare. Due to the absence of specific clinical manifestations, early diagnosis and treatment of these tumors are difficult to achieve.

CASE SUMMARY

A 37-year-old female patient visited our hospital due to numbness and swelling of the gums in the right lower molar area that had persisted for half a month. The patient's overall condition and intraoral examination revealed no significant abnormalities. She was initially diagnosed with a cystic lesion in the right mandible. However, after a more thorough examination, the final pathological diagnosis was confirmed to be neurofibroma. Complete tumor resection and partial removal of the right inferior alveolar nerve were performed. As of writing this report, there have been no signs of tumor recurrence for nine months following the surgery.

CONCLUSION

This case report discusses the key features that are useful for differentiating solitary intraosseous neurofibromas from other cystic lesions.

A case report: Pain in the hand and tingling of the upper limb may be a symptom of a schwannoma in the supraclavicular region

INTRODUCTION

Schwannomas, or neurilemmomas, are rare benign nerve sheath tumors primarily originating from peripheral nerves. Brachial plexus schwannomas, constituting approximately 5 % of cases, present a diagnostic and surgical challenge due to their rarity and the complex anatomy of the brachial plexus.

CASE PRESENTATION

We present the case of a 51-year-old man who visited our physiotherapy clinic with a two-year history of intermittent pain and tingling in the fourth and fifth metacarpals of his non-dominant hand (Numeric Pain Rating Scale 2/10). The pain was nocturnal and resistant to various treatments. Physical examination did not reveal "red flag" symptoms. Considering the persistent and atypical nature of the symptoms, further diagnostic investigations, including an ultrasound of the supraclavicular region, were recommended.

CLINICAL DISCUSSION

Our case report emphasizes the importance of considering brachial plexus schwannomas in patients with prolonged and unconventional symptoms in the fourth and fifth digits, accompanied by supraclavicular swelling and a positive Tinel's sign. Comprehensive diagnostic evaluation is crucial to confirm or rule out a schwannoma in the supraclavicular area. The rarity of such tumors and the intricate brachial plexus anatomy require meticulous diagnostic and surgical approaches.

CONCLUSIONS

This case adds to the growing understanding of brachial plexus schwannomas and their diagnostic complexities. Our report underscores the significance of recognizing these tumors in patients with distinct symptomatology and highlights the need for detailed diagnostic assessments and surgical planning.

An Extensive Unilateral Nasal Mass: Septal Schwannoma-Case Report

Schwannomas are benign peripheral nerve sheath tumours that arise from the Schwann cells of the myelinated nerve and may occur throughout the body. Paranasal schwannomas are uncommon lesions, representing less than 4% of all head and neck schwannomas and nasal septal schwannomas are very rare. Here we report a rare case of sinonasal schwannoma in a 46-year-old male who presented with a history of progressive nasal blockage of 3 years duration. The mass was removed by endoscopic approach without any postoperative complication. The rarity of diagnosis was aided by immune histopathology (IHC) of the tissue to confirm the disease.

Cervical Sympathetic Chain Schwannoma-Our Experience

Tumours arising from the parapharyngeal space are uncommon. The most common tumour arising primarily from this region is a neurogenic tumour, especially Schwannoma. The most common site of origin of a Schwannoma in parapharyngeal space is Vagus nerve. Cervical sympathetic chain (CSC) schwannomas are extremely rare. Here, we discuss a case of a 30-year old female with cervical sympathetic chain schwannoma, the clinical presentation, diagnosis and management.

Large lumbosacral schwannoma in a young female- a case report from Afghanistan

INTRODUCTION

Mobile Schwannoma is a rare soft tissue tumor that commonly involves the elderly population. It has no cellular material and grows as solitary, firm, oval, encapsulated benign tumors from the sensory (dorsal) nerve root. If multiple, they are usually associated with Neurofibromatosis type 2 (NF-2). The initial sign and symptoms include segmental pain and paresthesia. It may lead to myelopathy if the tumor expands.

CASE PRESENTATION

We present a twenty-year-old female with chronic lower backache radiating to the ipsilateral thigh with no urinary or fecal incontinence. On physical examination, the ankle reflex was hypoactive on the left side, and the straight leg raise test was positive. A large 32 × 15 × 14 mm heterogeneous enhancing focal lesion was found on the posterior side of L5 and S1 vertebrae with severe central canal stenosis. A diagnosis of nerve sheath tumor was made based on contrast MRI pre-operatively. The underlying cause was a nerve sheath tumor. A total bilateral laminectomy at the L1-S5 level and mass excision was performed, preserving nerve roots. The postoperative period was uneventful, and no tumor re-growth was noticed.

CLINICAL DISCUSSION

Schwannoma is a slow-growing tumor; benign; usually, less than 8 cm in diameter tumor, commonly found in the head and neck region. It is the 3rd most common soft tissue tumor and the 2nd most common intradural extramedullary tumor. In our report, a young, non-Caucasian female patient is diagnosed with schwannoma, which is quite rare. In our case, a larger tumor of size 32 × 15 × 14 mm was noted, affecting the posterior body of L5 and S1 vertebrae in the left lateral recess with impingement of the left S1 traversing nerve root. Around 29% of spinal root nerve tumors are schwannomas. As the tumor grows slowly, the diagnosis may be delayed.

CONCLUSION

Schwannoma is a slow-growing solitary, firm, oval, encapsulated benign tumor arising from the sensory (dorsal) nerve root. Histopathology plays a vital role in diagnosis, and overall, the disease has a favorable prognosis. Therefore, an appropriate approach is necessary to rule out the disease.

Guyon Canal Syndrome Due to Schwannomas of Zone 3 Ulnar Nerve without Neurologic Symptoms: A Case Report

We report a mass without neurologic findings and moderate pain in a 33-year-old male's wrist at the 3^rd zone of the ulnar nerve due to schwannoma that was excised successfully, and the patient was free of symptoms. We further discuss the prevalence and management of this lesion.

Retroperitoneal shwannoma: A case report

INTRODUCTION

Schwannomas are tumors that arise from Schwann cells of the peripheral nerve sheath and rarely occur in the retroperitoneum (3% of all schwannomas). Patients are usually asymptomatic or have nonspecific symptoms, making accurate preoperative diagnosis difficult. Schwannomas are usually benign, but infrequently undergo malignant transformation. Herein, we report a case of retroperitoneal schwannoma and review the relevant literature.

PRESENTATION OF CASE

A 25-year-old woman presented to our department with a 2-year history of abdominal pain that was localized in the right flank without radiation, constipation/diarrhea or externalized digestive hemorrhage. On physical examination, we found a painless palpable mass in the right hypochondrium extending to the right iliac fossa, measuring approximately 10 cm. The MRI and CT scan showed the presence of a large intra-abdominal oval formation in the right para-umbilical region. It was well limited, measuring 110*69mm with discrete irregular contours, thickened wall and heterogeneous content mostly fluid. They also showed the presence of a cystic formation in the right ovary measuring 84*52mm and extending over 76mm. The procedure consisted of resection of the retroperitoneal solid cystic mass, right ovariectomy and drainage of the right parietal-colic gutter by Salem sump tube. A laparotomy with a median incision above and below the umbilicus was performed. After the resection, the specimens were sent for anatomopathological examination which concluded that the retroperitoneal mass was a schwannoma and the ovarian mass was a serous cystadenoma.

DISCUSSION

Retroperitoneal schwannomas are rare tumors and a pre-operative diagnosis is often difficult. The diagnosis is most often fortuitous and late, given the latency of the tumor's evolution, and the definitive diagnosis is based on histopathologic examination. Herein we presented a case of retroperitoneal schwannoma and studied the features of this phenomenon on the basis of the literature.

CONCLUSION

Retroperitoneal schwannomas are rare. The diagnosis is often late at the stage of a large tumor. Radiologic findings are usually nondiagnostic. The treatment of choice is complete surgical excision. Prognosis is good but because of the risk of recurrence and malignant transformation, further follow-up is necessary.

Giant lumbar spinal schwannoma: a case report and literature review

We report a case of a 40-year-old female patient admitted to the hospital due to lumbar pain that spread to both legs and was associated with weakness of the lower extremities. Magnetic resonance imaging revealed an intradural - extramedullary tumor at the level of the T12 - L2 vertebra. The lesion was over 7 cm in greatest diameter and compressed the conus medullaris. The patient underwent surgery to remove the entire tumor. Postoperative pathology confirmed the diagnosis of schwannoma. The symptoms resolved almost completely without significant complications.

Schwannomas of Uncommon Peripheral Locations: Analysis of Imaging Findings of 21 Cases

BACKGROUND

Schwannomas are benign slow-growing tumors most often associated with the cranial nerves. Schwannomas often originate from the eighth cranial nerve. They may also originate from the peripheral nervous system of the neck and extremities. However extracranial peripheral schwannomas are considered a rare entity.

OBJECTIVES

The knowledge of rare localizations and typical imaging findings will lead to a successfulradiological diagnosis. Therefore, in this study, we present the clinical findings and MRI characteristics of schwannomas with a rare localization involving the peripheral, lower and upper extremity and intramuscular regions.

MATERIALS AND METHODS

The hospital database was screened for patients with an extracranial soft tissue mass. Twenty-one cases of schwannomas were found in rare localization. We analyzed the MR images of these patients retrospectively. The MR images were evaluated in terms of tumor location, signal intensity, and enhancement pattern. The histological examination of all the patients confirmed the diagnosis of schwannoma.

RESULTS

In 21 patients, the schwannomas were peripheral, localized to upper (n = 6) and lower extremities (n = 11). The remaining four patients had intramuscular schwannomas. The patients diagnosed with intramuscular schwannomas had schwannomas in sternocleidomastoid, gastrocnemius, triceps muscle and lateral wall of the abdomen. The average long-axis diameter of the tumor was 27.7 mm and the average short-axis diameter was 16.4 mm. The contrast pattern was diffused in eight tumors and peripheral in 13.

CONCLUSION

In this study, we present clinical findings and MRI characteristics of schwannomas with a rare localization involving the peripheral, lower and upper extremity and intramuscular regions.

Schwannoma of the Brachial Plexus: A Rare Case Report

Introduction:

Brachial plexus schwannomas are extremely rare tumours of the head and neck region accounting for less than 5 % overall. Due to its rarity and anatomic complexity of the brachial plexus, schwannomas in this region present a diagnostic and surgical challenge to the surgeon.

Case Report:

We present a case of a 56-year-old female who presented with a slow growing right sided neck swelling associated with pain and tingling in the distal end of the right forearm. According to FNAC, imaging studies results, a diagnosis of benign neurogenic tumour possibly schwannoma was made. After taking proper consent patient underwent surgical excision of the tumour. Postoperatively, patient developed numbness and tingling in right arm and stiffness at elbow joint, which is showing improvement after regular physiotherapy sessions.

Conclusion:

Although brachial plexus schwannomas are extremely rare head and neck tumours they should be kept as a differential diagnosis in patients presenting with supraclavicular neck swellings. These are potentially curable lesions. As such, detailed history and examination together with imaging studies is important in establishing a preoperative diagnosis for proper management.

DNA methylation in Schwann cells and in oligodendrocytes

DNA methylation is one of many epigenetic marks, which directly modifies base residues, usually cytosines, in a multiple-step cycle. It has been linked to the regulation of gene expression and alternative splicing in several cell types, including during cell lineage specification and differentiation processes. DNA methylation changes have also been observed during aging, and aberrant methylation patterns have been reported in several neurological diseases. We here review the role of DNA methylation in Schwann cells and oligodendrocytes, the myelin-forming glia of the peripheral and central nervous systems, respectively. We first address how methylation and demethylation are regulating myelinating cells' differentiation during development and repair. We then mention how DNA methylation dysregulation in diseases and cancers could explain their pathogenesis by directly influencing myelinating cells' proliferation and differentiation capacities.

Diffusion tensor imaging and tractography for preoperative assessment of benign peripheral nerve sheath tumors

PURPOSE

To evaluate the diagnostic value of fiber tractography and diffusivity analysis generated from 3D diffusion-weighted (DW) sequences for preoperative assessment of benign peripheral nerve sheath tumors.

METHOD

MR imaging at 3 T was performed in 22 patients (mean age 41.9 ± 17.1y, 13 women) with histologically confirmed schwannomas (N = 18) and histologically confirmed neurofibromas (N = 11), including a 3D DW turbo spin echo sequence with fat suppression. Diffusion tensor parameters were computed and fiber tracks were determined. Evaluation was performed by two radiologists and one orthopedic surgeon blinded for final diagnosis. Mean diffusivity was computed to allow further assessment of tumor microstructure. Preoperative fascicle visualization was graded, fascicles were categorized regarding anatomical location and amount of fascicles surrounding the tumor. The agreement of imaging findings with intraoperative findings was assessed.

RESULTS

On 78.3 % of the DTI images, the fascicle visualization was rated as good or very good. Tractography differences were observed in schwannomas and neurofibromas, showing schwannomas to be significantly more often located eccentrically to the nerve (94.8 %) than neurofibromas (0 %, P < 0.01). Fascicles were significantly more often continuous (87.5 %) in schwannomas, while in neurofibromas, none of the tracks was graded to be continuous (0 %, P = 0.014). A substantial agreement between fiber tracking and surgical anatomy was found regarding the fascicle courses surrounding the tumor (κ = 0.78). Mean diffusivity of schwannomas (1.5 ± 0.2 × 10^-3 mm²/s) was significantly lower than in neurofibromas (1.8 ± 0.2 × 10^-3 mm²/s; P < 0.001). The Youden index showed an optimal cutoff at 1.7 × 10^-3 mm²/s (sensitivity, 0.91; specificity, 0.78; J = 0.69).

CONCLUSIONS

Preoperative diffusion tensor imaging allowed to accurately differentiate between schwannomas and neurofibromas and to describe their location in relation to the nerve fascicles for preoperative planning.

Predictive factors of postoperative deficit and functional outcome after surgery for upper limb schwannomas: Retrospective study of 21 patients

Schwannomas are the most frequent benign tumors of the peripheral nerves. Tumor enucleation is the traditional surgical treatment. The incidence of neurological complications after surgery varies and predictive factors for these complications are not clearly defined. The aim of this study was to find predictive factors of postoperative neurological deficit after surgical treatment of schwannomas of the upper limb. Twenty-four schwannomas removed from 21 patients were analyzed retrospectively. The patients' mean age was 45.4years and the mean follow-up was 64.4months. Clinical parameters studied were age, gender, nature of preoperative symptoms, duration of symptoms, type of surgery performed, tumor location and size, nerve involved, QuickDASH and DN4 scores. Postoperative neurological deficits occurred in 14 patients (67%), with 11 having a sensory deficit and 7 a motor weakness. Eleven did not exist before surgery (6 sensory, 5 motor). In the postoperative deficit subgroup, 6 schwannomas involved the brachial plexus, 4 the ulnar nerve, and 4 the median nerve. All patients who had a fascicular resection because tumor enucleation was not feasible were in the postoperative deficit subgroup. Ten patients had either unchanged or worse QuickDASH and/or DN4 scores after surgery. Surgical treatment of schwannomas can lead to postoperative complications. Although none of our findings were statistically significant, advanced age, large tumor size, more than 16months between the first symptoms and surgery, and brachial plexus location seem to be more frequently observed in those with a postoperative neurological deficit.

Pelvic Schwannoma: In light of a case report

A 41-year-old man with abdominal enlargement, as a result of large retroperitoneal Schwannoma, was reported to our center. It was seen to have caused the displacement of the colon and was attached to the presacral region of the spine. Following the diagnosis, successful resection of Schwannoma was achieved.

Optimal surgical approaches and treatment outcomes in patients with jugular foramen schwannomas: a single institution series of 31 cases and a literature review

Complete resection of jugular foramen schwannomas (JFSs) with minimal cranial nerve complications remains difficult even for skilled neurosurgeons. Between November 2011 and November 2017, 31 consecutive patients diagnosed with JFSs underwent a single-stage operation performed by the same neurosurgeon. We retrospectively analyzed clinical characteristics, surgical approaches, treatment outcomes, and follow-up data for these patients. JFSs were classified according to the Samii classification system. A retrosigmoid approach was used to resect type A tumors, while a suboccipital transjugular process (STJP) approach was used to resect type B tumors. Notably, the present study is the first to report the use of a paracondylar-lateral cervical (PCLC) approach for the treatment of type C and D tumors. Type A-D tumors were observed in seven, four, four, and 16 patients, respectively. Gross-total resection was achieved in 29 patients (93.5%). There were no cases of intracranial hematoma, re-operation, tracheotomy, or death. Adjunctive gamma knife treatment was used to manage residual tumors in two patients. Neurological deficits relieved in half of patients at the last follow-up. By reviewing the studies published on PubMed, the approaches gradually be more conservative, rather than widely expose the skull base. Nonetheless, endoscope and stereotactic radiosurgery plays an important role in the management of JFSs. Both tumor removal and neurological function retention can be obtained by choosing individual treatment.

Age-dependent copy number variations of TP53 tumour suppressor gene associated with altered phosphorylation status of p53 protein in sporadic schwannomas

PURPOSE

Point mutations of TP53 tumour suppressor are very rare in schwannomas. We aim to characterize the frequency of exonic copy-number changes of the gene in the tumour and to examine the association between TP53 alterations, phosphorylation status of p53 protein and clinical phenotypes.

METHODS

The alterations of TP53 were screened by a combination of Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA) in a total of 44 vestibular schwannomas. The mutation index (MI) in a tumour was defined as the number of exons mutated/ the number of exons tested. Phosphorylation status of p53 protein was investigated by immunoblotting and immunofluorescence.

RESULTS

MLPA analysis showed single and multi-exon deletion mutations of TP53 in 65.7% of the cases. Comparisons of clinical features between mutated and non-mutated patients established an association of TP53 mutations with progressive phenotypes, including an earlier formation and a larger tumour. In addition, there were significant correlations between MI and both patients' age and tumour size. The Ser 392 phosphorylation level of p53 varied among tumours, and correlation analysis revealed an age-dependent phosphorylation pattern. The majority of tumours with hyperphosphorylated p53 were from mutated and young patients, suggesting an association of Ser392 phosphorylation with the mutational status of TP53 involved in the acceleration of tumour growth in young individuals. Moreover, Ser 392 phosphorylation contributed to a nuclear accumulation of p53 in schwannona cultures with TP53 mutation.

CONCLUSIONS

An interplay between the mutation status of TP53, phosphorylation patterns and tumour behaviors might be established in the disease.

Intraoperative Neurophysiologic Monitoring for Lumbar Intradural Schwannomas: Does It Affect Clinical Outcome?

OBJECTIVE

Intraoperative multimodal neuromonitoring (IONM) is considered valuable for the early detection and prevention of any neurologic compromise during spine surgery. It has also become the standard of care at many institutions to improve the surgical outcome and be a safety net for both clinical and medicolegal concerns.

METHODS

Our experience and outcomes in 46 consecutive cases of lumbar intradural schwannoma resection were reviewed with respect to clinical outcomes and patient safety, before and after the integration of IONM into our clinical practice.

RESULTS

Total surgical resection of schwannomas in the lumbar spine led to improved health-related quality of life for patients. The standard technique for microsurgical resection of schwannomas requires identifying and resecting the fiber of origin for the schwannoma, guided with triggered electromyographic monitoring. However, whether this changed the surgical strategy, because spinal roots that gave rise to the schwannoma were frequently found to be nonfunctional during surgery, remains unclear. In our series of 46 patients, we did not recognize any additional motor deficit after the surgery, regardless of the use of IONM.

CONCLUSIONS

Despite our analysis proving no difference in clinical outcomes with or without the use of IONM during surgical excision of lumbar schwannomas, we still prefer using IONM as a standard approach. It adds to the confidence and ease of mind of the surgeon during resection and also provides valuable data in cases of medicolegal disputes. However, it comes with an increased cost and lengthened surgical procedure.

Peripheral nerve injuries in the pediatric population: a review of the literature. Part III: peripheral nerve tumors in children

INTRODUCTION

Peripheral nerve tumors type, inciedence and treatment in the pediatric population should be analyzed.

METHODS

We have performed an extense literature review of this subject.

RESULTS

incidence and distribution are similar to those observed in adults. The most common peripheral nerve tumors in children are neurofibromas and schwannomas. Malignant peripheral nerve sheath tumors are also observed, specially associated with genetic syndromes, like neurofibromatosis and Carney complex.

CONCLUSION

In this review, peripheral nerve tumors have been divided into three categories to aid with understanding: reactive and hyperplastic lesions, benign tumors, and malignant tumors. The most frequent lesions have been described.

Endoscopic endonasal approach to primitive Meckel's cave tumors: a clinical series

INTRODUCTION

Recently, an alternative endoscopic endonasal approach to Meckel's cave (MC) tumors has been proposed. To date, few studies have evaluated the results of this route. The aim of our study was to evaluate long-term surgical and clinical outcome associated with this technique in a cohort of patients with intrinsic MC tumors.

METHODS

All patients with MC tumors treated at out institution by endoscopic endonasal approach (EEA) between 2002 and 2016 were included. Patients underwent brain MRI, CT angiography, and neurological evaluation before surgery. Complications were considered based on the surgical records. All examinations were repeated after 3 and 12 months, then annually. The median follow-up was of 44.1 months (range 16-210).

RESULTS

The series included 8 patients (4 F): 5 neuromas, 1 meningioma, 1 chondrosarcoma, and 1 epidermoid cyst. The median age at treatment was 54.5 years (range 21-70). Three tumors presented with a posterior fossa extension. Radical removal of the MC portion of the tumor was achieved in 7 out of 8 cases. Two patients developed a permanent and transitory deficit of the sixth cranial nerve, respectively. No tumor recurrence was observed at follow-up.

CONCLUSION

In this preliminary series, the EEA appeared an effective and safe approach to MC tumors. The technique could be advantageous to treat tumors located in the antero-medial aspects of MC displacing the trigeminal structures posteriorly and laterally. A favorable index of an adequate working space for this approach is represented by the ICA medialization, while tumor extension to the posterior fossa represents the main limitation to radical removal of this route.

Challenges in managing a vagal schwannomas: Lesson learnt

BACKGROUND

Paraganglioma of head and neck is a rare tumor and vagal schwannoma is even rarer. The majority of patients with vagal schwannoma presents with a lateral neck mass. Its management is delicate as the need to confirm the diagnosis by histopathology via a biopsy is contraindicated. Here, is a case of a young female with vagal schwannoma complicated with hoarseness after the biopsy of the mass, which persists after extirpation of the tumor.

CASE DESCRIPTION

A 22-year old lady presented with a history of a right neck mass for a 5-months duration. Clinical examination revealed a mass at level II neck region which measures 3.0 cm × 2.0 cm and it was mobile, non-pulsatile and had smooth surfaced. CT scan and angiogram showed that the mass arose between the carotid artery and vagal nerve and it was a highly vascular lesion. A CT scan-guided biopsy performed but complicated with neck hematoma and patient developed hoarseness. On follow up, her hoarseness persists and her tissue biopsy came back as schwannoma. She was counseled regarding surgery versus radiation for her treatment and she agreeable for surgery. Hence, surgical excision was performed and intraoperatively the mass visualized arising from the vagal nerve. Postoperatively however, her voice did not improve.

CONCLUSION

Vagal schwannoma is a rare paraganglioma of head and neck and the best treatment is still controversial. Unnecessary investigation and procedure should be avoided in order to reduce morbidity as well as improves patient's quality of life.

Synergistic effect of Nutlin-3 combined with MG-132 on schwannoma cells through restoration of merlin and p53 tumour suppressors

BACKGROUND

The great majority of sporadic vestibular schwannomas (VSs) are due to the mutations of the NF2 gene encoding merlin. Sporadic VSs exhibit variable growth patterns and only a small fraction of the tumours are fast-growing; however, the underlying mechanisms remain undefined.

METHODS

DNA sequencing and dosage analysis were used to identify the NF2 mutation status in sporadic schwannomas. The expression and sub-cellular localization of merlin and p53-MDM2 were assessed by immunoblotting, qRT-PCR and immunofluorescence. In vitro and in vivo studies were performed to reveal the effects of Nutlin-3 (a MDM2 inhibitor) and/or MG-132(a proteasome inhibitor) on schwannomas. The proliferation of schwannoma cells was assessed by CCK-8 assay, EdU staining and Flow cytometry analysis.

FINDINGS

Double genetic hits of NF2 tended to occur in fast-growing tumours, characterized by the absence of merlin. The deregulation of p53-MDM2 was demonstrated to mediate merlin-deficient tumour growth, characterized by a nuclear accumulation of stabilized MDM2, contributing to a nuclear export of p53 for degradation. Nutlin-3 blocked the proliferation of schwannoma cells via a cooperative recovery of merlin and p53, accompanied by the shuttling of both proteins from the cytoplasm to the nucleus. We further demonstrated a difference in the sensitivity to Nutlin-3 between schwannoma cells with and without merlin expression. Nutlin-3 combined with MG-132 narrowed this between-group difference and triggered stronger inhibitory effects on the growth of schwannomas through coordinated reactivation of p53.

INTERPRETATION

These findings present treatment strategies directed on the pathogenesis of sporadic schwannomas. FUND: National Natural Science Foundation of China.

Isolated Pediatric Intramedullary Schwannoma: Case Report and Review of Literature

BACKGROUND

Intramedullary (IM) schwannomas are rare entities representing 0.3%-1% of intramedullary tumors and 1.1% of spinal schwannomas. Beside many theories proposed, their rare occurrence might be related to the absence of Schwann cells in the spinal cord. Pediatric IM schwannomas are uncommon, and in the absence of neurofibromatosis they are extremely rare. To date, few cases have been reported in the literature.

CASE DESCRIPTION

We describe the case of an 8-year-old female affected by a progressive paraparesis. Neuroradiologic investigations showed an oval-shaped mass at the level of T10-T11. The patient underwent surgery, performed under neurophysiologic monitoring. The patient was operated on with complete removal of the lesion. The postoperative course was uneventful.

CONCLUSIONS

The clinical, neuroradiologic, and intraoperative findings are presented, along with a review of the literature. Despite the number of lesions potentially compressing the spinal cord, IM schwannoma is rare but should be taken into account in the differential diagnosis.

Gamma Knife Stereotactic Radiosurgery for Nonvestibular Cranial Nerve Schwannomas

BACKGROUND

Nonvestibular cranial schwannomas represent a rare type of benign intracranial tumor. Few studies have evaluated the use of stereotactic radiosurgery (SRS) as a primary management option for these lesions. We performed a retrospective review of our institution's experience focusing on efficacy with regard to tumor control and clinical symptom stabilization as well as treatment safety.

METHODS

Patients were included if they underwent at least 1 SRS procedure for a nonvestibular schwannoma and had at least 6 months of available imaging follow-up. Demographic, SRS dose planning, clinical, and imaging data were collected from chart reviews of treated patients. χ² and Kaplan-Meier analyses were performed.

RESULTS

Between 2004 and 2016, 35 schwannomas were treated in 34 patients. Median follow-up was 48 months. Median age at time of treatment was 51 years. Three patients had neurofibromatosis 2. Schwannoma location was trigeminal (57%), facial (20%), jugular foramen (14%), abducens (6%), and trochlear (3%). Median margin dose delivered was 13 Gy. The 5-year and 10-year tumor control rates were 94.4% and 88.5%, respectively. Presenting clinical symptoms stabilized or improved in 79% of cases after radiosurgery, and new or worsening symptoms were seen in 21%.

CONCLUSIONS

SRS is a safe and effective modality for treatment of nonvestibular cranial nerve schwannomas.

[Paracondylar-lateral cervical approach for resection of jugular foramen schwannomas: a retrospective analysis of 15 cases]

Objective: To explore the effects of paracondylar-lateral cervical approach for resection of the jugular foramen schwannoma(JFS). Methods: A total of 15 patients with JFS operated via the paracondylar-lateral cervical approach between December 2011 and March 2016 at Department of Neurosurgery in Xiangya Hospital of Central South University were retrospectively analyzed. There were 7 males and 8 females, aging from 22 to 77 years with a mean age of (41.9±15.8) years.There were 12 patients who accepted primary surgery, 3 patients who accepted secondary surgery. There were 10 patients with tinnitus or hearing loss, 8 patients with dysphagia, 9 patients with hoarseness, 7 patients with tongue hemiparesis, 8 patients with ataxia, 1 patient with Pyramidal signs, 2 patients with facial hypesthesia or pain, 1 patient with facial paresis. According to Samii JFS grading system, 2 patients were type B, 4 were type C and 9 were type D. All patients were followed-up through outpatient and telephone by MRI in 3, 9, 12 months postoperation. Results: Gross total removal of tumors were achieved in 14 patients and subtotal removal in 1 patient. Two patients had new hoarseness, 2 had new dysphagia and 3 had more serious dysphagia, 1 patient had more serious facial paresis after the operation. There were 2 patients with intracranial infection, 2 with pneumonia, 1 with subcutaneous effusion, 1 with cerebrospinal fluid rhinorrhea, 5 with gastric intubation during perioperative period. There were no death, intracranial hematoma and decreased hearing patients. All patients were followed up, the follow-up time were 3 to 33 months with a mean of (26.9±11.2) months. Till to the latest follow up, dysphagia improved in 2 cases, hoarseness and tongue hemiparesis improved in 3 cases, hearing loss and tinnitus improved in 9 cases, balance function improved in 7 cases, facial hypesthesia and pain improved in 2 cases, pyramidal signs disappeared in 1 case, facial nerve function improved to normal in 1 case. There was no recurrence and progressed case. Conclusion: Paracondylar-lateral cervical approach is an alternative approach for both intracranial and extracranial JFS.

Parapharyngeal space primary tumours

INTRODUCTION AND OBJECTIVES

The aim of this study is to present our experience with the diagnostic and therapeutic approaches for parapharyngeal space tumours.

PATIENTS AND METHOD

This study is a retrospective review of 90 patients diagnosed with tumours of the parapharyngeal space and treated surgically between 1984 and 2015. Patients whose tumours were not primary but invaded the parapharyngeal space expanding from another region, tumours originating in the deep lobe of the parotid gland and head and neck metastasis were excluded from this study.

RESULTS

74% percent of the parapharyngeal space neoplasms were benign and 26% were malignant. Pleomorphic adenoma was the most common neoplasm (27%), followed by paragangliomas (25%), miscellaneous malignant tumours (16%), neurogenic tumours (12%), miscellaneous benign tumours (10%), and malignant salivary gland tumours (10%). The transcervical approach was used in 56 cases, cervical-transparotid approach in 15 cases, type A infratemporal fossa approach in 13 cases, transmandibular approach in 4 cases and transoral approach in 2 cases. The most common complications were those deriving from nervous injuries.

CONCLUSIONS

Most parapharyngeal space tumours can be removed surgically with a low rate of complications and recurrence. The transcervical approach is the most frequently used.

Carney complex: A familial lentiginosis predisposing to a variety of tumors

Carney complex is a familial lentiginosis syndrome; these disorders cover a wide phenotypic spectrum ranging from a benign inherited predisposition to develop cutaneous spots not associated with systemic disease to associations with several syndromes. Carney complex is caused by PRKAR1A mutations and perturbations of the cyclic AMP-dependent protein kinase (PKA) signaling pathway. In addition to the cutaneous findings, the main tumors associated with Carney complex are endocrine: 1) primary pigmented nodular adrenocortical disease, a bilateral adrenal hyperplasia leading to Cushing syndrome; 2) growth-hormone secreting pituitary adenoma or pituitary somatotropic hyperplasia leading to acromegaly; 3) thyroid and gonadal tumors, including a predisposition to thyroid cancer. Other tumors associated with Carney complex include: 1) myxomas of the heart, breast and other sites; 2) psamommatous melanotic schwannomas which can become malignant; 4) a predisposition to a variety of cancers.

Endoscopic Facial Nerve Surgery

Tympanic facial nerve segment surgery has been traditionally performed using microscopic approaches, but currently, exclusive endoscopic approaches have been performed for traumatic, neoplastic, or inflammatory diseases, specially located at the geniculate ganglion, greater petrosal nerve, and second tract of the facial nerve, until the second genu. The tympanic segment of the facial nerve can be reached and visualized using an exclusive transcanal endoscopic approach, even in poorly accessible regions such as the second genu and geniculate ganglion, avoiding mastoidectomy, bony demolition, and meningeal or cerebral lobe tractions, with low complication rates using a minimally invasive surgical route.

Dumbbell Shaped Schwannoma of the Lateral Chest Wall masquandering as a soft tissue sarcoma

Schwannomas are benign, slow growing nerve sheath tumours of Schwann cell origin. They predominantly are known to involve the head, neck and the flexor surfaces of the extremities, retroperitoneum and the posterior spinal roots. The chest wall is a relatively uncommon location for a schwannoma, the vast majority of which are intra-thoracic, which are usually located in the posterior mediastinum and bulge into the thoracic cavity. Schwannomas arising from the lateral chest wall are relatively uncommon (<5 %). Dumbbell shaped schwannomas of the lateral chest wall i.e. with an intra-thoracic and extra-thoracic component, is extraordinarily rare and to the best of our knowledge only one case has been reported prior. We report possibly the second case of a dumbbell shaped lateral chest wall schwannoma in a 33-year-old female patient which masquandered as a case of soft tissue sarcoma.

Intrapetrous Internal Carotid Artery: Evaluation of Exposure, Mobilization and Surgical Maneuvers Feasibility from a Retrosigmoid Approach in a Cadaveric Model

OBJECTIVES

To provide a quantification of the exposure of the vertical and horizontal segments of the intrapetrous carotid artery (IPCA) and to evaluate the possibilities of its mobilization and of performing surgical maneuvers on it using the retrosigmoid approach.

METHODS

Twelve surgical dissections were performed bilaterally on 6 fresh cadavers. Predissection computed tomography (CT) scans with bone fiducials for intraoperative navigation were acquired. A retrosigmoid craniectomy was performed. The inframeatal space was drilled, the horizontal (HoIPCA) and vertical (VeIPCA) segments of the IPCA were exposed, and their measurements were recorded. The carotid canal was enlarged, the artery was carefully detached from the bone, and a vessel loop was inserted in order to mobilize its horizontal segment. Afterwards we performed different surgical maneuvers: We inflated a 5-French Fogarty balloon to compress the IPCA and repaired a 7-mm arteriotomy with a running suture. Specimens underwent a new CT scan to evaluate the amount of bone removal and the integrity of the inner ear structures.

RESULTS

The HoIPCA and VeIPCA were exposed and anatomically preserved in all specimens without injuring the surrounding neurovascular structures. The HoIPCA presented an average length of 24.89 mm (range: 19.41-31.47 mm), and the VeIPCA presented an average length of 10.07 mm (range: 8.92-11.58 mm). The possibility of IPCA mobilization and the feasibility of performing surgical maneuvers were demonstrated. Postdissection CT scan showed the preservation of inner ear structures.

CONCLUSION

Exposure and mobilization of the IPCA using a retrosigmoid approach are feasible and could represent a viable option for the possibility of reaching a total resection of selected skull base tumors, even when involvement of the carotid canal is present.

Porta hepatic schwannoma: case report and a 30-year review of the literature yielding 15 cases

Background

Schwannomas located in the periportal region are extremely rare. Only 14 cases have been reported in the medical literature worldwide. Cases of porta hepatic schwannomas reported in the literature worldwide were reviewed. As a result, it is very challenging for surgeons to make a preoperative diagnosis due to its rarity and nonspecific imaging manifestations.

Case Presentation

A 57-year-old Chinese female was admitted to our institution with complaint of upper abdominal distension and the abdominal CT in the local hospital revealed a hypodense mass in the porta hepatis. A fine needle aspiration (FNA) was made to confirm the diagnosis, but the result was just suggestive of spindle cell neoplasia. Eventually, the patient underwent surgery and postoperative pathology confirmed schwannoma in porta hepatis. The patient recovered uneventfully with no evidence of recurrence after a follow-up period of 41 months.

Conclusions

It is essential for the final diagnosis of porta hepatic schwannomas to combine histological examination with immunohistochemistry after surgery. The main treatment of porta hepatic schwannomas is complete excision with free margins and no lymph node dissection. In some cases, biliary reconstruction or the proper hepatic and the gastroduodenal artery resection was performed because the tumor was inseparably attached to the extrahepatic bile duct or the proper hepatic and the gastroduodenal artery. Malignant transformation of schwannomas is very rare and the overall prognosis is satisfactory.

Mystery of Sciatica Resolved - A Rare Case Report

Schwannomas are common, benign, slow growing tumours of peripheral nerve sheath arising from the schwann cells of the neuroectoderm. They do not transverse the nerve but remain within the sheath on top of the nerve. They rarely present in the sciatic nerve. Sciatic schwannomas may mimic symptoms of herniated disc, usually with radiation of pain to buttocks and thigh region with inability to walk for long distances and sometimes may present with claudication. In the absence of low back pain and with a normal Lumbo-Sacral MRI study, causes intrinsic to sciatic nerve needs to be thought off, which often delays the diagnosis. Rarity in our case-patient presented with tingling sensation and inability to squat on hard surface for more than 10 minutes with a normal x-ray and MRI study of lumbosacral spine.

Neurogenic tumors and tumor-like lesions of the oral and maxillofacial region: A clinicopathological study

Objective

Oral and maxillofacial lesions of neural origin are rare soft tissue neoplasms. The aim of the present study is to review the epidemiological data of oral and maxillofacial neurogenic lesions submitted for diagnosis to our laboratory over a 31-year period (August 1984–March 2015).

Materials and methods

The available formalin-fixed embedded specimens, Hematoxylin and Eosin slides, demographic and clinical data were retrieved.

Results

Thirty-one cases were included in this study, representing 0.6% of the 5161 biopsies submitted. Most of the diagnosed cases 11 (35.5%) were traumatic neuromas. The other cases included 2 (6.5%) solitary circumscribed neuromas, 2 (6.5%) melanotic neuroectodermal tumors of infancy, 2 (6.5%) Schwannomas, 5 (16.1%) granular cell tumors, and 9 (29%) neurofibromas. The patients’ ages ranged from 5 months to 78 years. Among these cases, 16 were males (51.61%) and 15 were females (48.38%).

Conclusion

This analysis showed that neural lesions affecting the oral and maxillofacial region were rare and mostly benign in nature. Such lesions should be carefully diagnosed because of their association with life-threatening syndromes and the possibility of malignant transformation.

Multiple schwannomas of the ulnar nerve

Schwannoma is a relatively uncommon benign tumour of the soft tissues. We present a rare case of 10 tumours localised to the ulnar nerve.

Endoscopic ultrasound features of gastric schwannomas with radiological correlation: A case series report

Gastric schwannomas are rare mesenchymal tumors of the gastrointestinal tract. They are usually misdiagnosed as other submucosal tumors preoperatively. Experience of the imaging features of gastric schwannomas is extremely limited. In this report, we summarize the features of a series of endoscopic ultrasound (EUS) images of gastric schwannomas in an effort to improve the diagnosis and differential diagnosis rate. We retrospectively reviewed the endosonographic features of four patients with gastric schwannomas and their computed tomography imaging results. Gastric schwannomas had heterogeneous hypoechogenicity or isoechogenicity, and a well-demarcated margin. The tumors originated from the fourth layer. Cystic changes and calcification were uncommon. Marginal hypoechoic haloes were observed in two patients. The results described here were different from those of previous studies. In the EUS evaluation, the internal echogenicity of gastric schwannomas was heterogeneous and low, but slightly higher than that of muscularis propria. These features might help us differentiate gastric schwannomas from other submucosal tumors. Further investigation is needed to differentiate these mesenchymal tumors.

Giant Posterior Mediastinal Ancient Schwannoma Requiring Thoracoabdominal Resection: A Case Report and Literature Review

Posterior mediastinal schwannomas are benign, slow growing nerve sheath tumors and rarely cause symptoms. We present a case of a 47-year-old man who presents with severe mid-back pain and dyspnea on exertion. Chest radiograph and computed topography revealed a large posterior mediastinum mass. Surgical resection required en bloc resection of a portion of the diaphragm, and wedge resection of the left lower lobe of the lung via left thoracoabdominal approach. Pathology was consistent with ancient schwannoma. This case is unique due to the location and size of the mass and the surgical approach required for complete resection.

Schwannoma of the hard palate

Schwannoma or neurilemmomas are benign, slow-growing, usually solitary, encapsulated tumors. They originate from the schwann cells of the nerve sheath. Approximately 30-40% of head and neck tumors are schwannomas. Intraoral schwannomas constitute a mere 1%. Tongue is the commonest site of schwannomas intraorally. Here we report a rare case of a hard palate swelling which was histopathologically diagnosed as schwannoma. The lesion was completely excised intraorally.

Laryngeal schwannomas-case reports with rare presentations

Schwannomas also known as Neurilemmomas are benign encapsulated, slow growing perineural tumours of Neuro-ectodermal origin that arise from the sheet of schwann cells. Two cases are being presented due to their rarity and in both cases the diagnosis was arrived at after the excision of the tumour.

Expression of Angiopoietin-1, 2 and 4 and Tie-1 and 2 in gastrointestinal stromal tumor, leiomyoma and schwannoma

AIM: To investigate the role of angiopoietin (Ang) -1, -2 and -4 and its receptors, Tie-1 and -2, in the growth and differentiation of gastrointestinal stromal tumors (GISTs).

METHODS: Thirty GISTs, seventeen leiomyomas and six schwannomas were examined by immunohistochemistry in this study.

RESULTS: Ang-1, -2 and -4 proteins were expressed in the cytoplasm of tumor cells, and Tie-1 and -2 were expressed both in the cytoplasm and on the membrane of all tumors. Immunohistochemical staining revealed that 66.7% of GISTs (20 of 30), 76.5% of leiomyomas (13 of 17) and 83.3% of schwannomas (5 of 6) were positive for Ang-1. 83.3% of GISTs (25 of 30), 82.4% of leiomyomas (14 of 17) and 100% of schwannomas (6 of 6) were positive for Ang-2. 36.7% of GISTs (11 of 30), 58.8% of leiomyomas (10 of 17) and 83.3% of schwannomas (5 of 6) were positive for Ang-4. 60.0% of GISTs (18 of 30), 82.4% of leiomyomas and 100% of schwannomas (6 of 6) were positive for Tie-1. 10.0% of GISTs (3 of 30), 94.1% of leiomyomas (16 of 17) and 33.3% of schwannomas (2 of 6) were positive for Tie-2. Tie-2 expression was statistically different between GISTs and leiomyomas (P < 0.001). However, there was no correlation between expression of angiopoietin pathway components and clinical risk categories.

CONCLUSION: Our results suggest that the angiopoietin pathway plays an important role in the differentiation of GISTs, leiomyomas and schwannomas.