Cerebellopontine Angle Schwannoma Research Articles

Intracochlear signal in FIESTA-C and hearings of patients with cerebellopontine angle schwannoma

Background Hearing loss in patients with cerebellopontine angle (CPA) schwannoma, is thought to be caused by the damage to the cochlea and the cochlear nerve. Aim This study aimed to examine the relationships between the intracochlear signal in magnetic resonance imaging (MRI) and hearing in patients with CPA schwannoma. Material and method In 79 patients with CPA schwannoma, we retrospectively examined the signal in the cochlea on the affected side was compared with that on the unaffected side to determine signal degradation in fast imaging reagents steady-state acquisition with cycle phases (FIESTA-C) MRI. For hearing evaluation, pure tone audiometry (PTA), speech audiometry, distortion product otoacoustic emissions (DPOAE), and auditory brainstem response (ABR) were used. For each parameter, we examined the differences between the groups with and without signal degradation. Results In the hearing test results, the I-wave latency of ABR was significantly longer in the group with signal degradation in FIESTA-C (1.84 ± 0.35 msec vs. 2.04 ± 0.37 msec, p = 0.048). There was no statistically significant difference in other tests. Conclusion The MRI signal changes in the cochlear were related to the I-wave latency of ABR and reflected cochlear function. Significance We suggested the cochlear signal changes in CPA schwannoma patients related the hearing.

Partial hypoglossal-facial neurorrhaphy: a surgical technique.

This is a video demonstration of hemihypoglossal-facial neurorrhaphy. Any irreversible facial palsy more than House-Brackmann grade II is aesthetically problematic. Also, the functional and psychological impact associated with a higher grade of facial palsy is even worse. In this video, the procedure is demonstrated in a female patient with irreversible grade VI facial palsy and corneal opacity due to exposure keratitis 1 year following surgical excision of cerebellopontine angle (CPA) schwannoma. Postoperative outcomes are shown in another patient who underwent a similar procedure for establishing outcomes. The nasolabial fold and eye closure symmetry can be achieved with minimal or no hypoglossal morbidity. The video can be found here: https://stream.cadmore.media/r10.3171/2022.10.FOCVID2290.

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 (MTRasym) 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 MTRasym values clearly differentiated between the schwannoma and meningioma groups. At an MTRasym value threshold of 0.024, the diagnostic sensitivity, specificity, positive predictive value, and negative predictive values for MTRasym were 88.9%, 77.8%, 80.0%, and 87.5%, respectively. Our results demonstrated the ability of MTRasym values on APT-CEST imaging to discriminate patients with schwannomas from patients with meningiomas.

Matched Cohort Analysis of the Effect of the Facial Recess Approach on Cerebrospinal Fluid Leak After Translabyrinthine Surgery for Schwannoma.

The facial recess approach during translabyrinthine surgery has been used to expose the eustachian tube (ET) for packing. We sought to determine the effect of this technique on the development of postoperative nasopharyngeal cerebrospinal fluid (CSF) leaks. Cohorts of patients with cerebellopontine angle schwannomas who underwent a facial recess approach or no facial recess approach were matched based on tumor size. Translabyrinthine surgery for tumor resection. Postoperative CSF leaks were recorded and nasopharyngeal CSF leaks were utilized as the primary outcome measure. Using an exact matching protocol based on tumor size, 102 patients were included in each group (204 total, 111 female, 93 male). Overall, 9 patients (4.4%) demonstrated a postoperative nasopharyngeal CSF leak. Postoperative CSF rhinorrhea was noted in 3.9% of the group who underwent a facial recess approach for packing of the ET and 4.9% of the group who did not undergo a facial recess approach. This rate was not significantly different between groups (p = 0.99, Odds ratio: 0.79, 95% CI: 0.15-3.8). Secondary variables including age, tumor size, a diagnosis of NF2, and the packing material used were not significant predictors of nasopharyngeal CSF leaks. CSF rhinorrhea is infrequent after translabyrinthine surgery. The incidence of this complication is not affected by whether or not a facial recess approach is performed during surgery to pack the ET. Based on these data, use of this technique should be based on surgeon comfort and preference.

Comorbidity of cerebellopontine angle meningioma with other primary neoplasms

Background Meningioma is known to be accompanied by other primary neoplasms, yet has been evaluated less than these. Objective This study investigated comorbidity of cerebellopontine angle (CPA) meningioma with other primary neoplasms. Methods Overall 1,085 meningioma cases including 16 meningiomas at the CPA were enrolled for investigating the presence of other primary neoplasms. Another 16 age-, sex-, and size-matched CPA schwannoma were also included for comparison. Results Of a data-base cohort study of overall 1085 meningioma cases, 165 cases (15%) were associated with other primary neoplasms. In contrast, 8 (50%) of 16 CPA meningioma and one (8%) of 16 CPA schwannoma showed other primary neoplasms. Except for one patient who had oral cancer prior to the diagnosis of CPA meningioma by 4 years, the interval from diagnosis of CPA meningioma to that of other primary neoplasm ranged 0–6 (mean, 3.1 ± 2.5) years. Conclusion Prevalence of comorbidity with other primary neoplasms is significantly higher in CPA meningioma (50%) than overall meningioma (15%) and CPA schwannoma (8%). In addition to follow-up MR imaging to visualize both residual tumor and regional brain environment after treatment of CPA meningioma, long-term systemic screening for other primary neoplasm is also mandatory.

Neuropati Optik Kompresif Bilateral yang Terinduksi oleh Schwannoma

The aim of this case report was to present further study about diagnosis and management of bilateral compressive optic neuropathy induced by schwannoma. This case report will discuss about the definition, classification, etiology, clinical diagnosis and treatment for compressive optic neuropathy. A case report. 43 years-old woman complained about blurred vision since 2 years ago. She also complained about pain on her right head while she was walking. There was no history of tinnitus or hearing loss. She had a history of contraception pill uses and progesterone injection every 3 months for 5 years alternately. She also suffered from schwannoma in cerebello pontine angle based on MRI and histopathology examination. From physical examination, best corrected visual acuity on right eye was 5/6 PHNI and on left eye was 5/8 PHNI. Ishihara test showed decreased colour vision. There was also ataxic gait. From anterior segment examination, there were decreased light reflex and RAPD. From posterior segment examination, there were papilloedema and elevation on both eyes proved by OCT and fundal imaging. Neuroprotector therapy and surgery show a good result. Ishihara test are improving, light reflex are increasing and there are no RAPD anymore. From posterior segment, papilloedema are slowly diminished. The patient presents a case of bilateral compressive optic neuropathy induced by schwannoma. Neuroprotector and surgery show a good result.

Intratemporal facial nerve schwannomas: multicenter experience of 80 cases.

To provide more data on the clinical presentation and natural evolution of facial nerve schwannomas and to provide guidance for therapeutic decision making. A retrospective case review of eighty patients diagnosed with a facial nerve schwannoma between 1990 and 2018 in ten tertiary referral centers in Europe was performed. Patients' demographics, symptomatology, audiometry, anatomical site (segments involved), size and whenever possible volume measurement were registered. At presentation, transient or persistent facial palsy was the most common symptom, followed by hearing loss. The schwannoma involved more than one segment in the majority of the patients with the geniculate ganglion being most commonly involved. Initial treatment consisted of a wait and scan approach in 67.5%, surgery in 30% and radiation therapy in 2.5% of the patients. Tympanic segment schwannomas caused mainly conductive hearing loss and were more prone to develop facial palsy at follow-up. Internal auditory canal or cerebellopontine angle schwannomas presented with significantly more sensorineural hearing loss. Although modern imaging has improved diagnosis of this tumor, choosing the best treatment modality remains a real challenge. Based on the literature review and current findings, more insights into the clinical course and the management of facial nerve schwannomas are provided.

Cerebellopontine angle schwannomas arising from the intermediate nerve: a scoping review.

Intermediate nerve schwannomas (INS) are extremely rare lesions in literature. They have been described mimicking facial nerve schwannomas, but not vestibular schwannomas (VS). We aimed to review the previously published cases, as well as the evidence to believe that they are far more common, though usually misdiagnosed as facial or VS. We performed a review of PubMed/Medline and Embase of "intermediate nerve schwannoma," "facial nerve schwannoma," "greater superficial petrosal nerve schwannoma," "geniculate ganglion schwannoma," and "chorda tympani schwannoma" to identify all cases of INS, following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) statement. Furthermore, 2 cases operated at our center are shown to exemplify the proposed hypotheses. No article was excluded from review. Thirteen cases of INS, 11 cases of chorda tympani schwannoma, and 18 cases of greater superficial petrosal nerve schwannoma were found in literature. In facial nerve schwannomas, the predilection of schwannomas for sensory nerves, and the ability to preserve the motor facial nerve during tumor resection support the hypothesis of intermediate nerve as the nerve of origin. For VSs, the different arachnoidal arrangement of medial VS, the sharing of pia mater by the intermediate nerve and vestibular nerve, and the medial Obersteiner-Redlich zone of the intermediate nerve, support the hypothesis of intermediate nerve origin of some VS. The correct identification of the intermediate nerve as a nerve of origin of cerebellopontine angle schwannomas is of uttermost importance, especially when mistaken for VS, as this may account for the heterogeneity of facial and cochlear outcomes after surgery.

Metastatic mucinous adenocarcinoma presenting as cerebellopontine angle tumor

Intracranial posterior fossa metastasis is a common entity. Metastatic mucinous adenocarcinoma presenting as cerebellopontine angle (CPA) tumor is very rare. The authors presented a 47-year-old female patient with right CPA tumor. The magnetic resonance imaging brain showed a heterogeneous contrast-enhancing dural-based extra-axial right CPA lesion involving the right cerebellar hemisphere, internal auditory meatus, and posterior surface of the right petrous bone. The patient underwent surgery, and subtotal resection of the tumor was done. Histology of the tumor was metastasis from a mucinous adenocarcinoma. Contrast-enhanced computed tomography scan of the abdomen and pelvis, ultrasound of the thyroid, chest X-ray, and thyroid function tests were normal. Carbohydrate antigen (CA) 19-9 was 949.37 U/mL, serum carcinoembryonic antigen (CEA) was 48.17 ng/mL, and CA-125 was 8.20 U/mL. In view of the raised CA 19-9 and CEA, primary malignancy was believed to be arising from the pancreas or from the gastrointestinal tract, though the definitive diagnosis of primary malignancy was not made. Although rare, metastatic mucinous adenocarcinoma should be kept in the differential diagnosis of CPA lesions. Even though the tumor is radiologically mimicking as CPA schwannoma, the absence of hearing abnormality should raise the suspicion for other diagnoses.

Trigeminal Nerve Schwannoma of the Cerebellopontine Angle.

Introduction Large and even moderate sized, extra-axial cerebellopontine angle (CPA) tumors may fill this restricted space and distort the regional anatomy. It may be difficult to determine even with high resolution magnetic resonance imaging (MRI) if the tumor is dural-based, or what the nerve of origin is if a schwannoma. While clinical history and exam are helpful, they are not unequivocal, particularly since many patients present with a myriad of symptoms, or conversely an incidental finding. We present an atypical appearing, asymptomatic CPA tumor, ultimately identified at surgery to be a trigeminal schwannoma. Case History A 40-year-old man presented with new-onset seizure. MRI identified an incidental heterogeneously contrast-enhancing CPA lesion ( Fig. 1A – D ). The tumor was centered on the internal auditory canal (IAC) with no tumor extension into Meckel's cave, IAC or jugular foramen. Audiometry demonstrated 10db of relative left-sided hearing loss with 100% word recognition. Physical examination was negative for focal neurologic deficits. A retrosigmoid craniotomy was performed and an extra-axial, yellow-hued mass was encountered and resected, which was ultimately confirmed to originate from the trigeminal nerve ( Video 1 ). Gross total resection was achieved, and the patient recovered from surgery with partial ipsilateral trigeminal sensory loss and no other new neurologic deficits. Conclusion Pure CPA trigeminal schwannomas are rare, but should be considered in the differential for enhancing CPA lesions. Although, Meckel's cave involvement is frequently observed, it is not universal, and pure CPA schwannomas of all cranial nerves IV–XII have been reported in the literature. The link to the video can be found at: https://youtu.be/AlodYCu70F8 .

Laryngeal reinnervation in unilateral vocal fold paralysis- case report and literature review

Laryngeal reinnervation is the method of treatment in unilateral vocal fold paralysis. During the surgery an anastomosis between the main branch of ansa cervicalis and recurrent laryngeal nerve is formed. Regeneration of the nerve’s functional abilities is a long process, lasting from 4 to 6 months, up to a year. A 35 year-old male was admitted to the Department of Otolaryngology at Warsaw Medical University in order to undergo surgical removal of reoccurrence of Schwannoma in left cerebellopontine angle by translabyrinthine approach. Post-operative period was complicated with vagal nerve paralysis. The patient reported hoarseness, dysphagia and choking. Physical examination revealed left vocal fold immobilization in abducted position, saliva in piriform fossa and left-sided soft palate paralysis yet the patient was discharged home. 4 weeks after the surgery, the patient was admitted to the hospital again due to developing aspiration pneumonia. Augmentation of the left vocal fold with calcium hydroxyapatite was performed 2 months later. After this intervention temporary vocal improvement and choking frequency reduction was observed. Finally, the patient underwent laryngeal reinnervation with formation of ansa cervicalis main branch to recurrent laryngeal nerve anastomosis. Left vocal fold regained its functional abilities and the quality of the voice improved. Laryngovideostroboscopy performed 6 months later revealed mobilization of left vocal fold sufficient for proper glottis closure. The voice measures normalized and the swallowing improved. Conclusions This case report and analyzed data confirm that laryngeal reinnervation surgery in unilateral vocal fold paralysis helps achieve satisfactory effects in voice function and life quality.

An Unusual Variant of Cerebellopontine Angle Schwannoma in a Young Nepalese Girl

An unusual variant of cerebellopontine angle schwannomas is extremely rare. Histologically, the tumor has atypical changes misleading the diagnosis. We report 20-year-old Nepalese girl from far-eastern community presented with features of raised intracranial pressure and difficulty in walking. MR imaging revealed intensely contrast enhanced well defined huge solid tumor in right cerebellopontine angle region with foci of multiple cystic components. The tumor was displacing the brain stem structures with dilatation of lateral and third ventricles. The altered radiological finding made discrepancy diagnosis. Conventional angiography demonstrated major feeders from the auricular branch of the right external carotid artery. The tumor was embolized with polyvinyl alcohol particles followed by gross total lateral suboccipital excision. Histopathology unit detailed it as ancient schwannoma with pleomorphic changes.

Susceptibility weighted imaging - a problem-solving tool in differentiation of cerebellopontine angle schwannomas and meningiomas.

Background and purpose Vestibular schwannomas and meningiomas of the cerebellopontine angle can be differentiated by the presence of foci of blooming on susceptibility weighted imaging. Materials and methods In this retrospective study, magnetic resonance imaging with susceptibility weighted imaging sequence in addition to other routine sequences was done in 73 patients. All the cases were studied for the presence of foci of blooming within the tumor on susceptibility weighted imaging. Histopathological examination confirmed the diagnosis in all cases. Results There were 59 patients in the vestibular schwannoma group and 14 in the meningioma group. Susceptibility weighted imaging showed presence of blooming (due to microhemorrhages) in all the cases of cerebellopontine angle schwannomas. In the meningioma group, 13 cases showed no blooming within the lesion; one case showed blooming which was confirmed to be due to calcification on computed tomography study. For the detection of foci of blooming and predicting histopathologic diagnosis of schwannoma pre-operatively, susceptibility weighted imaging showed a sensitivity of 100%, specificity of 92%, positive predictive value of 98.3%, and negative predictive value of 100%. The Fisher exact test showed a statistically significant difference in the differentiation of vestibular schwannoma from meningioma on the basis of detection of blooming on susceptibility weighted imaging ( p < 0.0001). Conclusion Susceptibility weighted imaging is a problem-solving tool in making accurate pre-operative differentiation of vestibular schwannoma from meningioma.

Postoperative Complications and Readmission Rates Following Surgery for Cerebellopontine Angle Schwannomas.

To investigate the 30-day postoperative complication, readmission, and reoperation rates following surgery for cerebellopontine angle (CPA) schwannomas. Cross-sectional analysis. National surgical quality improvement program dataset (NSQIP) 2009 through 2013. All surgical cases with an International Classification of Diseases, 9th edition, Clinical Modification (ICD-9-CM) diagnosis code of 225.1, benign neoplasms of cranial nerves, and one of the following current procedural terminology (CPT) codes, were included: 61616, 61526, 61530, and 61520. Surgical resection as indicated by the CPT codes above. Demographics, comorbidities, 30-day postoperative complications, readmission rate, and reoperation rate. Overall, 404 cases were identified, of which 42.6% were men. The average age was 51 years. Comorbidities were present in 45.3%. NSQIP-tracked complications occurred in 9.7% of patients. Most common complications were wound infections including surgical-site infection and wound dehiscence (11 patients, 2.7%), sepsis (10 patients, 2.5%), blood loss (nine patients, 2.2%), and deep vein thrombosis (DVT; seven patients, 1.7%). Mortality occurred in four patients (1.0%). The complication rate was statistically higher in patients with comorbidities versus those without (10.2% versus 4.1%, p = 0.04). Patients with complications were more likely to undergo reoperation (2.5% with versus 4.1% without, p = 0.001). Unplanned readmissions occurred in 41 cases (10.1%) and reoperations occurred in 23 patients (5.7%). Most common NSQIP-tracked complications in excision of CPA neoplasms are infections, sepsis, blood loss, and deep vein thrombosis (DVT). Further, investigation of patients with unplanned readmission and reoperation are warranted. Neurotologists need to take an active role in the data to be gathered in the NSQIP database as it relates to vestibular schwannomas.

Morphometric analysis of posterior fossa in Indian CP angle acoustic schwannoma patients.

Aim:To study the morphometry of posterior fossa in Indian CP angle schwannoma patients in order to know its influence on the extent of excision of the CP angle acoustic schwannomas.Materials and Methods:One hundred cases of cerebellopontine angle schwannomas treated surgically by the senior author and 20 controls between January 2006 and June 2011 were consecutively investigated with computed tomography (CT) using the high-resolution CT bone windows before surgery. Evaluation of anatomic parameters of the petrous bone and posterior fossa cavity were done in all patients and controls. Data were entered in Excel software and were analyzed using NCSS software. All possible regression analysis was done to select the important variables to be included in the model to predict the excision of tumor with these variables. A prediction model was developed defining the binary outcome as total excision or subtotal excision as dependent variable and the morphometric data and grading of tumor as independent variables.Results:Interpetrous distance (IP) is the distance between the two petrous apices. Sigmoid distance (IS) distance is the distance between the two sigmoid points. Sigmoid point is the point at which the scalloped impression of the sigmoid sinus straightens to join the occipital bone posteriorly. SAG is the distance between the mid IP point and the mid-point on the inner wall of the occipital bone. The PM angle was 47.8±4.14 degrees (38-58), the PA angle was 42.68±4.47 degrees (34-53), the IP distance was 2.07±0.13 cm (1.5-2.8), the sagittal diameter of posterior fossa was 6.22±0.73 cm (5.1-9.8) and the intersigmoid distance was 9.45±0.73 cm (7.4-11). There was no significant gender difference in the posterior fossa morphometry between patients and controls. Inter-sigmoid distance and the petrous-apex angle were more in the Indians when compared to the European population mentioned in the Mathies and Samii study.Conclusions:The posterior fossa morphological parameters of the Indian and European population differ significantly. Inter-sigmoid distance and the petrous-apex angle were more in the Indians when compared to the Europeans. There is no significant gender difference in the morphometry of the Indians. There is no significant difference between the patients and the control groups. In our study the adhesions with surrounding structures along with the posterior fossa morphometry significantly affect the extent of excision.

Stitchless fibrin glue-aided facial nerve grafting after cerebellopontine angle schwannoma removal: technique and results in 15 cases.

To evaluate the results of facial nerve (FN) grafting using great auricular cable graft and fibrin glue without suturing to palliate FN disruption after removal of large cerebellopontine angle (CPA) vestibular schwannoma (VS) or facial nerve schwannoma (FNS). To assess whether tumor size and origin influenced the results. Retrospective review of all patients having undergone removal of FNS/VS and needing intraoperative FN repair between 2001 and 2011. FN was rehabilitated using great auricular nerve cable graft and fibrin glue (Tisseal) without stitching suture. All data recorded were reviewed to access age, sex, tumor type, and tumor size according to the Koos classification and presenting symptoms. FN function was evaluated preoperatively and at 18 months using the House-Brackmann (HB) grading system. Among the 595 patients operated for CPA schwannomas in this period, 15 patients (2.5%) underwent FN repair, including 7 cases of FNS and 8 cases of VS. Tumor removal was total in all cases. FN recovery was HB3 in 13 cases (86.7%) and HB4 in 2. The mean time to the first clinical signs of facial reinnervation was 10 months (6-12 mo). No significant relation was found between postoperative facial function and tumor size or type, even if all cases of preoperative FP were noted in FNS. Immediate FN reconstruction with fibrin glue-aided greater auricular nerve graft can effectively restore FN function with excellent outcomes. The results seem better than those observed by other authors using sutured grafts or delayed hypoglossal-facial nerve anastomosis.

Role of magnetic resonance imaging in evaluation of cerebellopontine angle schwannomas.

The aim of the present study was to evaluate the role of Magnetic Resonance Imaging (MRI) to localize and characterize the MR imaging features of cerebellopontine angle schwannomas and to compare with surgical/histopathological findings. It was a prospective study which included 19 patients, who presented with signs and symptoms s/o any lesion in the CP angle and were referred to the radiology department for MRI. All patients included in the study were subjected to detailed clinical history and physical examination following which MRI was carried out on Philips Gyroscan Achieva 1.5 Tesla unit and the standard protocol consisted of T1WI, T2WI, DWI and FLAIR images in axial, sagittal and coronal planes. Hearing abnormality was the most common presenting complaint in patients with CP angle schwannoma's followed by headache and tinnitus. Vestibulocochlear nerve was the most commonly involved nerve in patients with these lesions followed by involvement of trigeminal nerve. MRI was erroneous in giving provisional diagnosis of schwannoma in one case, which on subsequent surgery and histopathology was found to be a meningioma. The sensitivity of MRI for correctly diagnosing vestibular schwannoma was 100% and specificity was 92.86% with a positive predictive value of 94.12% and accuracy of 96.67%. MRI is considered as an excellent noninvasive investigation for CP angle schwannoma's. It can identify the site and extension of the lesions as well as the characteristic signal. Apart from diagnosing, MR imaging plays an important role in stratifying patients into appropriate treatment options.

Stitchless Fibrin Glue-Aided Facial Nerve Grafting after Cerebellopontine Angle Schwannoma Removal: Technique and Results in 15 Cases

Stitchless Fibrin Glue-Aided Facial Nerve Grafting after Cerebellopontine Angle Schwannoma Removal: Technique and Results in 15 Cases

Acute Hemorrhage into Schwannomas of the Cerebellopontine Angle is an Uncommon, Life-Threatening Complication of Large Tumors

Objective: Hemorrhage into tumors has well been described in head and neck tumors. With regard to the cerebellopontine angle (CPA), this is a rarer entity. Because of its localization, however, it can be linked to severe complications. Study Design: We present two cases of known lateral skull base schwannomas that represented with acute deterioration in their condition. Management and prognosis are presented. Patients: These cases involved a 68-year-old woman with a 47 × 34 × 47 mm vestibular schwannoma (VS) with expansion of the internal acoustic meatus and no hydrocephalus. The second case was of a 64-year-old lady with a 34×40× 68mm bulbar nerve schwannoma expanding the jugular foramen also with no evidence of hydrocephalus. The patient with the bulbar schwannoma was managed conservatively due to the lack of cranial nerve palsies and symptoms and her reluctance for surgery. The patient with the vestibular schwannoma was awaiting surgery after a period of observation as the patient was initially reluctant for surgery. Both patients deteriorated suddenly and rapidly. CT showed hemorrhage into the tumors. Debulking of the vestibular schwannoma via the retrosigmoid approach was achieved while hemorrhage in the second case was fatal. Conclusion: Hemorrhage into large CPA schwannomas is rare but can be catastrophic. This should, however, be considered when patients with known large skull base schwannomas suddenly deteriorate. Urgent diagnostic imaging is indicated.

Angiosarcoma arising in schwannoma of cerebellopontine angle and later associating with meningioma in a patient with neurofibromatosis type 2

Here, we describe an extremely rare case of angiosarcoma arising in schwannoma of the cerebellopontine angle and later associating with meningioma in a patient with neurofibromatosis type 2. A 33-year-old disabled Japanese man with right drop foot after surgery for an unspecified tumor demonstrated multiple tumors, suspected to be schwannoma, in the bilateral cerebellopontine angles, the cervical and lumbar spinal cord, and on the right nuchal skin. Also present were several tumors in the medulla and thoracic spinal cord suspected to be ependymoma or astrocytoma. The patient was diagnosed with neurofibromatosis type 2 according to the diagnostic criteria by the U.S. National Institutes of Health. The bilateral tumors in the cerebellopontine angle were resected to reduce symptoms and brain stem compression. Histopathological analysis revealed angiosarcoma arising in schwannoma of the bilateral tumors, and angiosarcoma was proportionally larger in the right tumor than in the left. At age 36, the patient underwent a second resection of the regrown tumor in the left cerebellopontine angle, and histopathology demonstrated mixed angiosarcoma and meningioma. That angiosarcoma arises in schwannoma is a pathogenesis within the realm of conjecture, especially that the phenomenon of mixed meningioma and angiosarcoma has not been reported to date.