Sigmoid colon schwannoma is a rare benign gastrointestinal tumor that is challenging to be diagnosed preoperatively.This paper reported a case of sigmoid colon schwannoma that was preoperatively misdiagnosed as a gastrointestinal stromal tumor on ultrasonography.Intraoperative frozen section analysis identified it as a spindle cell tumor,with definitive diagnosis confirmed as gastrointestinal schwannoma via immunohistochemistry.This paper summarizes the similarities and differentiating features of intestinal stromal tumors and schwannomas on ultrasonographic imaging.By analyzing and discussing previous literature,we aim to enhance the diagnostic and differential diagnostic capabilities of ultrasonographers in preoperative evaluation of intestinal schwannomas,thereby providing reliable evidence for clinicians in the diagnosis and management of this condition.
Humans ; Neurilemmoma/diagnostic imaging* ; Ultrasonography ; Sigmoid Neoplasms/diagnostic imaging* ; Male ; Colon, Sigmoid/diagnostic imaging* ; Middle Aged ; Female ; Diagnosis, Differential

Objective:To summarize the initial experience and evaluate the technical feasibility of the endoscopic transcanal transpromontorial approach（TTA） for vestibular schwannoma resection by analyzing long-term follow-up outcomes. Methods:A retrospective analysis was conducted on the perioperative and long-term follow-up data（mean follow-up time: 5 years） of patients who underwent endoscopic TTA for vestibular schwannoma resection in the Department of Otorhinolaryngology Head and Neck Surgery at Xiangya Hospital, Central South University, between January 2020 and December 2020. Long-term outcomes were systematically evaluated. Results:This study included two patients（one 41-year-old male and one 51-year-old female）. According to the AAO-HNS hearing classification system, preoperative hearing was Class C in one patient and Class D in the other. Preoperative imaging confirmed Koos stageⅠ tumors in both cases. Postoperative transient facial nerve paralysis（House-Brackmann Grade Ⅲ） recovered to Grade Ⅰ within 4 months. No complications such as cerebrospinal fluid leakage, intracranial infection, or intracranial hemorrhage occurred. No tumor recurrence was observed during the 5-year follow-up period. Conclusion:The endoscopic transcanal transpromontorial approach is minimally invasive, facilitates rapid recovery, and demonstrates satisfactory technical feasibility and safety when strict patient selection criteria（Koos stageⅠtumors with non-serviceable hearing） are applied.
Humans ; Neuroma, Acoustic/surgery* ; Male ; Adult ; Middle Aged ; Retrospective Studies ; Female ; Endoscopy/methods* ; Follow-Up Studies ; Treatment Outcome

Objective:To analyze the clinical characteristics and risk factors of postoperative first bite syndrome（FBS） after parapharyngeal space surgery, and to provide evidence-based recommendations for the diagnosis and management of this complication. Methods:A retrospective analysis was conducted on 142 patients undergoing parapharyngeal space surgery from March 2016 to November 2024, including 12 cases of postoperative FBS. Univariate analysis compared differences in tumor location, pathological type, and surgical approach between FBS and non-FBS groups. Multivariate logistic regression identified independent risk factors. A systematic literature review evaluated the preventive value of transoral endoscopic surgery for FBS, followed by proposed clinical optimization strategies. Results:The incidence of FBS was 8.45%（12/142）. Univariate analysis revealed significant associations with: Superior parapharyngeal space tumors（OR=3.21, 95%CI 1.12-9.21, P=0.029）; Schwannoma pathology（OR=4.05, 95%CI 1.35-12.18, P=0.013）; Traditional lateral cervical approach（OR=5.67, 95%CI 1.89-17.02, P=0.002）. Multivariate analysis confirmed lateral cervical approach（aOR=4.98, 95%CI 1.62-15.31, P=0.005） and schwannoma（aOR=3.75, 95%CI 1.22-11.51, P=0.021） as independent risk factors. Literature review suggested lower FBS rates with transoral endoscopic approaches. The overall effect of the drug on FBS is poor. Conclusion:FBS is a frequent complication of parapharyngeal space surgery, significantly associated with tumor location, pathology, and surgical approach. Transoral endoscopic surgery can effectively reduce the risk of FBS through precise anatomical dissection that minimizes sympathetic nerve injury. Minimally invasive approaches are recommended for eligible cases.
Humans ; Retrospective Studies ; Postoperative Complications/etiology* ; Risk Factors ; Endoscopy ; Parapharyngeal Space/surgery* ; Male ; Female ; Adult ; Middle Aged ; Neurilemmoma/surgery*

OBJECTIVES

To highlight the clinical presentation, diagnostic dilemma and proposed management of a case of a transmodiolar intralabyrinthine schwannoma.

Design:Case Report

Setting:Tertiary National University Hospital

Patient:One

A 51-year-old woman consulted for a 12-year history of unilateral sensorineural hearing loss and progressively worsening vertigo. Workups revealed a hyperintense lesion approximating the entire right cochlea on Gadolinium-enhanced magnetic resonance imaging and profound hearing loss on the right on pure-tone audiometry, with no recordable response even at maximum intensity levels across all frequencies. Infectious and metastatic workups returned negative results, clinching the radiographic diagnosis of an intralabyrinthine schwannoma.

Intralabyrinthine schwannomas (ILS) are rare, benign neoplasms of the 8th cranial nerve, manifesting as progressive unilateral sensorineural hearing loss and worsening vertigo. These neoplasms are mainly detected by MRI; underdiagnosis and lack of standard treatment and diagnostic protocols result in their inaccurate diagnosis and delays in management.

Objective:This study aimed to analyze the results of auditory and vestibular function tests in patients with unilateral vestibular schwannoma and explore their association with tumor size. Methods:Clinical data from 81 patients diagnosed with unilateral vestibular schwannoma who underwent pure-tone audiometry（PTA）, cervical and ocular vestibular evoked myogenic potentials（c/oVEMP）, as well as video head impulse test（vHIT）, and subsequently underwent surgical treatment, were retrospectively analyzed. Patients were categorized into groups based on tumor size: small （≤ 15 mm）, medium（16-30 mm）, and large （>30 mm）, determined by the maximum tumor diameter on contrast-enhanced MRI scans. Results:PTA results indicated hearing loss in 73 cases（90.1%）; vestibular function tests revealed abnormal rates for the anterior semicircular canal, horizontal semicircular canal, posterior semicircular canal, utricle, and saccule at 29.6%, 77.8%, 54.3%, 90.1%, and 92.6%, respectively. Statistically, no significant differences were found in preoperative hearing test results among patients in different groups（F=0.393, P=0.676）. However, significant differences were observed in horizontal semicircular canal gain（r=-0.248, P=0.025）, abnormal rates of horizontal semicircular canal catch-up saccades（r=0.507, P<0.001）, as well as cVEMP（χ²=15.111, P=0.004） and oVEMP thresholds（χ²=18.948, P<0.001） across varying tumor size groups. Conclusion:The extent of hearing loss in patients with vestibular schwannoma is not correlated with tumor size, whereas the degree of vestibular dysfunction demonstrates a correlation with tumor size.
Humans ; Neuroma, Acoustic/physiopathology* ; Retrospective Studies ; Audiometry, Pure-Tone ; Vestibular Function Tests ; Vestibular Evoked Myogenic Potentials ; Female ; Male ; Head Impulse Test ; Middle Aged ; Adult ; Semicircular Canals/physiopathology* ; Aged ; Hearing Loss/physiopathology*

Objective: To examine the feasibility and surgical approach of removing type D trigeminal schwannoma through nasal cavity and nasal sinus under endoscope. Methods: Eleven patients with trigeminal schwannoma who were treated in the Department of Otorhinolaryngology, Qilu Hospital of Shandong University from December 2014 to August 2021 were analyzed retrospectively in this study. There were 7 males and 4 females, aged (47.5±13.5) years (range: 12 to 64 years). The neoplasm involved the pterygopalatine fossa, infratemporal fossa, ethmoidal sinus, sphenoid sinus, cavernous sinus, and middle cranial fossa. The size of tumors were between 1.6 cm×2.0 cm×2.0 cm and 5.7 cm×6.0 cm×6.0 cm. Under general anesthesia, the tumors were resected through the transpterygoid approach in 4 cases, through the prelacrimal recess approach in 4 cases, through the extended prelacrimal recess approach in 2 cases, and through the endoscopic medial maxillectomy approach in 1 case. The nasal endoscopy and imaging examination were conducted to detect whether neoplasm recurred or not, and the main clinical symptoms during follow-up. Results: All the surgical procedures were performed under endonasal endoscope, including Gross total resection in 10 patients. The tumor of a 12-year-old patient was not resected completely due to huge tumor size and limited operation space. One patient was accompanied by two other schwannomas located in the occipital region and the ipsilateral parotid gland region originating from the zygomatic branch of the facial nerve, both of which were removed concurrently. After tumor resection, the dura mater of middle cranial fossa was directly exposed in the nasal sinus in 2 cases, including 1 case accompanied by cerebrospinal fluid leakage which was reconstructed by a free mucosal flap obtained from the middle turbinate, the other case was packed by the autologous fat to protect the dura mater. The operation time was (M(IQR)) 180 (160) minutes (range: 120 to 485 minutes). No complications and deaths were observed. No recurrence was observed in the 10 patients with total tumor resection during a 58 (68) months' (range: 10 to 90 months) follow-up. No obvious change was observed in the facial appearance of all patients during the follow-up. Conclusion: Type D trigeminal schwannoma involving pterygopalatine fossa and infratemporal fossa can be removed safely through purely endoscopic endonasal approach by selecting the appropriate approach according to the size and involvement of the tumor.
Male ; Female ; Humans ; Child ; Retrospective Studies ; Endoscopy/methods* ; Nasal Cavity/surgery* ; Neurilemmoma/surgery* ; Cranial Nerve Neoplasms/surgery*

Objective: To investigate the application of cochlear nerve action potential (CNAP) monitoring in the resection of vestibular schwannoma, especially evaluating its significance for hearing preservation. Methods: From April 2018 to December 2021, 54 patients with vestibular schwannoma who underwent resection via retrosigmoid approach were collected in Chinese PLA General Hospital. Before surgery, all patients had effective hearing (AAO-HNS grade C or above). Brainstem auditory evoked potential (BAEP) combined with CNAP monitoring was performed during surgery. The CNAP monitoring was combined with continuous monitoring and cochlear nerve mapping. And patients were divided into hearing preservation group and non-preserved group according to postoperative AAO-HNS grade. SPSS 23.0 software was used to analyze the differences of CNAP and BEAP parameters between the two groups. Results: A total of 54 patients completed intraoperative monitoring and data collection, including 25 males (46.3%) and 29 females (53.7%), aged 27-71 years with an average age of 46.2 years. The maximum tumor diameter were (18.1±5.9) mm (range 10-34 mm). All tumors were totally removed with preserved facial nerve function (House-Brackmann grade I-II). The hearing preservation rate of 54 patients was 51.9% (28/54). During surgery, the V wave extraction rate of BAEP waveform was 85.2% (46/54) before tumor resection, 71.4% (20/28) in the hearing preservation group after tumor resection, and disappeared in the hearing preservation group (0/26). CNAP waveform was elicited in 54 patients during operation. Differences were found in the distribution of CNAP waveforms after tumor resection. The waveforms of the hearing-preserving group were triphasic and biphasic, while those in the non-preserving group were low-level and positive. For hearing preservation group, the amplitude of N1 wave after tumor resection was significantly higher than that before tumor resection[14.45(7.54, 33.85)μV vs 9.13(4.88, 23.35)μV, P=0.022]; However, for the non-preserved group, the amplitude of N1 wave after tumor resection was significantly lower than that before tumor resection [3.07(1.96, 4.60)μV vs 6.55(4.54, 9.71)μV, P=0.007]; After tumor resection, the amplitude was significantly higher than that of the unreserved group [14.45(7.54, 33.85)μV vs 3.07(1.96, 4.60)μV, P<0.001]. Conclusions: BAEP combined with CNAP monitoring is conducive to intraoperative hearing protection, and the application of cochlear nerve mapping can prompt the surgeon to avoid nerve injury. The waveform and N1 amplitude of CNAP after tumor resection have a certain value in predicting postoperative hearing preservation status.
Female ; Male ; Humans ; Middle Aged ; Neuroma, Acoustic/surgery* ; Action Potentials ; Evoked Potentials, Auditory, Brain Stem ; Cochlea ; Cochlear Nerve

OBJECTIVE: To report on a rare case of Neurofibromatosis type 2 (NF2) manifesting as oculomotor nerve palsy and explore its genetic basis. METHODS: A patient with NF2 who had presented at Beijing Ditan Hospital Affiliated to Capital Medical University on July 10, 2021 was selected as the study subject. Cranial and spinal cord magnetic resonance imaging (MRI) was carried out on the patient and his parents. Peripheral blood samples were collected and subjected to whole exome sequencing. Candidate variant was verified by Sanger sequencing. RESULTS: MRI revealed bilateral vestibular Schwannomas, bilateral cavernous sinus meningiomas, popliteal neurogenic tumors, and multiple subcutaneous nodules in the patient. DNA sequencing revealed that he has harbored a de novo nonsense variant of the NF2 gene, namely c.757A>T, which has replaced a codon (AAG) encoding lysine (K) at position 253 with a stop codon (TAG). This has resulted in removal of the Merlin protein encoded by the NF2 gene from position 253 onwards. The variant was not found in public databases. Bioinformatic analysis suggested that the corresponding amino acid is highly conserved. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was rated as pathogenic (PVS1+PS2+PM2_Supporting+PP3+PP4). CONCLUSION The heterozygous nonsense variant c.757A>T (p.K253*) of the NF2 gene probably underlay the disease in this patient with an early onset, atypical but severe phenotype.
Male ; Humans ; Neurofibromatosis 2/genetics* ; Genes, Neurofibromatosis 2 ; Oculomotor Nerve Diseases/genetics* ; Computational Biology ; Genomics ; Mutation

Objective: To explore the value of electrically evoked auditory brainstem response (EABR) monitoring combined with brainstem auditory evoked potential (BAEP) and compound action potential (CAP) monitoring during vestibular schwannoma resection for the protection of the cochlear nerve. Methods: Clinical data from 12 patients with vestibular schwannomas who had useful hearing prior to surgery were analyzed at the PLA General Hospital from January to December 2021. Among them, there were 7 males and 5 females, ranging in age from 25 to 59 years. Before surgery, patients underwent audiology assessments (including pure tone audiometry, speech recognition rate, etc.), facial nerve function evaluation, and cranial MRI. They then underwent vestibular schwannoma resection via the retrosigmoid approach. EABR, BAEP, and CAP were simultaneously monitored during surgery, and patients' hearing preservation was observed and analyzed after surgery. Results: Prior to surgery, the average PTA threshold of the 12 patients ranged from11 to 49 dBHL, with a SDS of 80% to 100%. Six patients had grade A hearing, and six patients had grade B hearing. All 12 patients had House-Brackman grade I facial nerve function prior to surgery. The MRI indicated tumor diameters between 1.1 and 2.4 cm. Complete removal was achieved in 10/12 patients, while near-total removal was achieved in 2/12 patients. There were no serious complications at the one-month follow-up after surgery. At the three-month follow-up, all 12 patients had House-Brackman grade I or II facial nerve function. Under EABR with CAP and BAEP monitoring, successful preservation of the cochlear nerve was achieved in six of ten patients (2 with grade B hearing, 3 with grade C hearing, and 1 with grade D hearing). Successful preservation of the cochlear nerve was not achieved in another four patients (all with grade D hearing). In two patients, EABR monitoring was unsuccessful due to interference signals; however, Grade C or higher hearing was successfully preserved under BAEP and CAP monitoring. Conclusion: The application of EABR monitoring combined with BAEP and CAP monitoring during vestibular schwannoma resection can help improve postoperative preservation of the cochlear nerve and hearing.
Male ; Female ; Humans ; Adult ; Middle Aged ; Neuroma, Acoustic/complications* ; Hearing/physiology* ; Evoked Potentials, Auditory, Brain Stem/physiology* ; Cochlear Nerve ; Hearing Loss, Sensorineural/etiology* ; Retrospective Studies ; Postoperative Complications/prevention & control*

Humans ; Child ; Nasal Bone ; Neurilemmoma/surgery*