Multicystic acoustic schwannoma with intratumoral hemorrhage: a report of two cases

"When the Benign Bleed" Vestibular Schwannomas with Clinically Significant Intratumoral Hemorrhage: A Case Series and Review of the Literature

Vestibular schwannomas (VSs) are slow-growing benign neoplasms commonly located at the cerebellopontine angle. Although clinically significant hemorrhagic VSs are rarely encountered with only 75 patients previously reported, they could be life threatening. We discuss the presentation and outcomes of three patients with hemorrhagic VS as well as review the literature for this phenomenon. Consecutive adult patients with a histologically proven diagnosis of VS over a 9-year period were retrospectively reviewed. Fifty adult patients were identified with three (6%) having clinically significant intratumoral hemorrhage. This was defined as patients having acute to subacute symptoms with frank radiological evidence of hemorrhage. The mean age of diagnosis was 62 ± 9 years and the male-to female ratio was 2:1. The mean duration of symptoms, namely headache, vertigo, and sensorineural hearing impairment, was 26 ± 4 days with one patient presenting with acute coma. Retrosigmoid craniotomy for tumor resection was performed for all patients. Histopathological examination revealed extensive areas of microhemorrhage with considerable macrophage infiltration. All three patients were discharged with no additional neurological deficit and good functional performance. Clinically significant hemorrhagic VSs are rare, and patients may present with acute to subacute (i.e., within a month) symptoms of hearing loss headache, facial, or trigeminal nerve palsy. Macrophage infiltration is frequently encountered in tumor specimens and reflects the pivotal role of chronic inflammation in their pathophysiology. Surgical resection can lead to good outcomes with timely intervention.

The Clinical Implications of Spontaneous Hemorrhage in Vestibular Schwannomas

Background  Spontaneous hemorrhage into vestibular schwannomas (VSs) is rare and can render more rapid symptom onset and a seemingly poorer prognosis for an otherwise benign pathology. We describe our series of hemorrhagic VS (HVSs) and systematically reviewed the literature to better understand relevant clinical factors and outcomes. Methods  Retrospective case review series and systematic review of the literature using PRISMA guidelines. Results  Fifty-three patients with HVS met inclusion criteria. Compared with historical data for all VS, patients with HVS had relatively higher rates of perioperative mortality, significant preoperative facial weakness, and harbored relatively larger tumors. Regardless of the extent of resection (EOR), surgery for HVS resulted in significant improvement of facial weakness ( p  = 0.041), facial numbness ( p  < 0.001), vertigo ( p  < 0.001), and headache ( p  < 0.001). Patients with facial weakness tended to have larger tumors ( p  = 0.058) on average and demonstrated significant improvement after surgery, irrespective of EOR ( p  < 0.01). The use of blood-thinning medications did not affect patient health outcome. Histopathology of HVS samples showed an increased number of dilated/ectatic thin-walled vascular channels, reflective of potentially increased vascular permeability and hypervascularity. Conclusion  HVS may be an aggressive subgroup of VS, associated with a surprisingly high mortality rate. When features of HVS are identified on imaging, these patients should be treated expeditiously, especially given that facial nerve dysfunction, which is identified in more than half of patients with HVS, appears to be reversible. Overall, this study has significant implications in the management of VS, raising awareness of a small, but highly morbid subgroup.

Sudden neurological deterioration due to repeated intratumoral hemorrhage in a patient with a vestibular schwannoma

Vestibular schwannomas (VS) are the most common tumors involving the cerebellopontine angle (CPA) and the internal auditory canal (IAC). These tumors are usually slow-growing and commonly present with cranial nerve dysfunction such as hearing loss. Repeated intratumoral hemorrhage (ITH) is extremely rare with only four cases previously reported. We report the case of a 30 year old female with a right sided CP angle tumor who presented with vertigo and ataxia due to ITH. Her symptoms initially improved; however, three weeks later, she had acute onset of facial palsy and imaging confirmed rebleeding. Surgical pathology reported typical features of schwannoma. A literature review performed using the PubMed and EMBASE databases yielded four previous reports. A summary of these cases is presented and the features of ITH are discussed. Patients affected by repeated ITH present with sudden headache and ataxia. Rapid worsening of cranial nerve dysfunction such as hearing loss or facial nerve palsy is suggestive of ITH.

Tumor-associated hemorrhage in patients with vestibular schwannoma

OBJECT

Intratumoral hemorrhage (ITH) associated with vestibular schwannomas (VS) is very rare. We retrospectively analyzed VS patients presenting with ITH in our department to further gain a better understanding of this uncommon clinical presentation.

METHODS

We treated seven patients who had VS presenting with ITH between January 2012 and June 2017. All the patients had preoperative computed tomography (CT), computed tomography angiography (CTA), and magnetic resonance imaging(MRI) done which aided in the radiological diagnosis as well as postoperative MRI to confirm the resection extent of the VS. Continuous electrophysiological monitoring of cranial nerves was carried out during surgery.

RESULTS

Of the seven patients, three were male and four were female. Their ages ranged from 42 to 71 years (average age, 57.4 years). Two patients reported a history of hypertension. Sudden onset or rapid worsening of clinical symptoms occurred in five patients at time of hemorrhage. The mean diameter of the lesions was 4.1 cm (range, 3.0-5.0 cm). No patient had a pretreatment of stereotactic radiosurgery. Gross total resection was achieved in four cases and subtotal resection in three cases. There were no surgery-related neurological deficits but one patient died 18 days after surgery. Follow-up visits were scheduled at 6 months postoperatively and two patients had tumor recurrence and received stereotactic radiosurgery again.

CONCLUSIONS

The incidence of ITH in VS is relatively rare and hypertension may highly correlate with ITH in VS. In comparison with peritumoral adhesion caused by chronic inflammation in multicystic VS with microhemorrhage,ITH caused by acute massive hemorrhage will not increase the extent of peritumoral adhesion immediately. The prognosis of surgery for patients with acute hemorrhagic VS may be better than that for microhemorrhage in multicystic VS. Besides, timely microsurgical treatment is also important to relieve symptoms.

Clinically significant intratumoral hemorrhage in patients with vestibular schwannoma

OBJECTIVES

The frequency of intratumoral hemorrhage (ITH) in vestibular schwannoma (VS) remains undefined.

METHODS

Retrospective case series of all patients diagnosed with hemorrhagic VS between 2003 and 2015 at a single tertiary academic skull base center.

RESULTS

Five patients with ITH were evaluated, representing 0.4% of all newly diagnosed VS evaluated at the authors' center during this time. The median age at time of diagnosis was 66 years (range 39-83), four of five cases occurred in men, and all had sporadic unilateral tumors. The frequency of ITH among patients receiving anticoagulation was 5.6% (2 of 36), compared to only 0.2% (3 of 1356) in non-anticoagulated patients (P = 0.006), representing a 25-fold increase. At time of hemorrhage, all patients had acute onset of headache, disequilibrium, and progression of hearing loss; three reported trigeminal symptoms, and two exhibited acute moderate facial paresis. The median tumor size at diagnosis of hemorrhage was 3.1 cm (range 2.4-4.2 cm), and three patients had radiological evidence of hydrocephalus. All patients underwent microsurgical resection. There were no perioperative deaths. At a median follow-up of 25 months (3-70 months), no patient has experienced tumor recurrence.

CONCLUSION

Tumor-associated hemorrhage in VS occurs in 0.4% of cases and commonly presents with acute neurological change. The risk of clinically significant hemorrhage is greater in patients receiving anticoagulation compared to the general VS population. Prompt microsurgical resection should be pursued when possible since tumor removal may improve neurological symptoms, relieve brainstem compression, and reduce the risk of repeat hemorrhage.

LEVEL OF EVIDENCE

4. Laryngoscope, 127:1420-1426, 2017.

Fluid-fluid level in cystic vestibular schwannoma: a predictor of peritumoral adhesion

OBJECT

The aim of this study was to evaluate the clinical results and surgical outcomes of cystic vestibular schwannomas (VSs) with fluid-fluid levels.

METHODS

Forty-five patients with cystic VSs and 86 with solid VSs were enrolled in the study. The patients in the cystic VSs were further divided into those with and without fluid-fluid levels. The clinical and neuroimaging features, intraoperative findings, and surgical outcomes of the 3 groups were retrospectively compared.

RESULTS

Peritumoral adhesion was significantly greater in the fluid-level group (70.8%) than in the nonfluid-level group (28.6%) and the solid group (25.6%; p < 0.0001). Complete removal of the VS occurred significantly less in the fluid-level group (45.8%, 11/24) than in the nonfluid-level group (76.2%, 16/21) and the solid group (75.6%, 65/86; p = 0.015). Postoperative facial nerve function in the fluid-level group was less favorable than in the other 2 groups; good/satisfactory facial nerve function 1 year after surgery was noted in 50.0% cases in the fluid-level group compared with 83.3% cases in the nonfluid-level group (p = 0.038).

CONCLUSIONS

Cystic VSs with fluid-fluid levels more frequently adhered to surrounding neurovascular structures and had a less favorable surgical outcome. A possible mechanism of peritumoral adhesion is intratumoral hemorrhage and consequent inflammatory reactions that lead to destruction of the tumor-nerve barrier. These findings may be useful in predicting surgical outcome and planning surgical strategy preoperatively.

Hemorrhagic vestibular schwannoma: review of the literature

BACKGROUND

Clinically significant intratumoral hemorrhage historically has been reported in only a small fraction of vestibular schwannomas (VS). Patients with hemorrhagic VS are more likely to present with neurologic deficits and have worse outcomes than patients with nonhemorrhagic VS. The purpose of this study is to analyze characteristics that may predispose VS to hemorrhage and that may prove helpful in the management and treatment of VS.

METHODS

A literature search was conducted using National Library of Medicine and National Institutes of Health databases to identify articles pertaining to intratumoral hemorrhage in VS. The authors selected 39 cases, described in 18 published articles, to review.

RESULTS

Average patient age and tumor size in hemorrhagic cases of VS did not differ significantly from nonhemorrhagic cases of VS. Facial nerve dysfunction at presentation occurred with greater frequency in cases of hemorrhagic VS (33.3%) than in nonhemorrhagic VS (6.0%). Death occurred much more frequently in cases of hemorrhagic VS (10.0%) than in nonhemorrhagic VS (0.2%). Abnormality of tumor-associated vasculature was noted histologically in many cases, and a large number of the cases reported prior treatment by stereotactic radiosurgery.

CONCLUSIONS

Understanding the origins and clinical implications of intratumoral hemorrhage in VS could potentially assist in clinical decision making and patient counseling.

The newly diagnosed vestibular schwannoma: radiosurgery, resection, or observation?

OBJECT

Management recommendations for patients with smaller-volume or newly diagnosed vestibular schwannomas (< 4 cm(3)) need to be based on an understanding of the anticipated natural history of the tumor and the side effects it produces. The natural history can then be compared with the risks and benefits of therapeutic intervention using a minimally invasive strategy such as stereotactic radiosurgery (SRS).

METHODS

The authors reviewed the emerging literature stemming from recent recommendations to "wait and scan" (observation) and compared this strategy with published outcomes after early intervention using SRS or results from matched cohort studies of resection and SRS.

RESULTS

Various retrospective studies indicate that vestibular schwannomas grow at a rate of 0-3.9 mm per year and double in volume between 1.65 and 4.4 years. Stereotactic radiosurgery arrests growth in up to 98% of patients when studied at intervals of 10-15 years. Most patients who select "wait and scan" note gradually decreasing hearing function leading to the loss of useful hearing by 5 years. In contrast, current studies indicate that 3-5 years after Gamma Knife surgery, 61%-80% of patients maintain useful hearing (speech discrimination score > 50%, pure tone average < 50).

CONCLUSIONS

Based on published data on both volume and hearing preservation for both strategies, the authors devised a management recommendation for patients with small vestibular schwannomas. When resection is not chosen by the patient, the authors believe that early SRS intervention, in contrast to observation, results in long-term tumor control and improved rates of hearing preservation.

Immunohistochemical expression of thrombomodulin in vestibular schwannoma

Many vestibular schwannomas (VS) manifest intratumoral microhemorrhages whose underlying mechanisms are not fully understood. Thrombomodulin (TM) is an endothelial anticoagulant cofactor that promotes the thrombin-mediated formation of activated protein C that inhibits thrombus formation. We investigated the existence of TM in VS and its potential role in the development of microhemorrhages. We used immunohistochemical staining to study the expression of TM in tissues derived from 25 patients with VS. Hemosiderin deposition was examined by Berlin blue staining and compared with the expression of TM. Vascular endothelial cells in all 25 VS tissues expressed TM. The TM-positive vessel ratio, calculated by dividing the number of TM-positive by the number of CD34-positive lumens, was significantly higher in hemosiderin-laden than hemosiderin-negative tissues (0.71 ± 0.17 vs. 0.53 ± 0.31, p = 0.049, Mann-Whitney U test). Our findings suggest a close relationship between the expression of TM and microhemorrhage in VS.

Vestibular Schwannomas presenting with haemorrhage: clinical presentation and histopathological evaluation of an unusual entity

Gross intratumoral haemorrhage is rare in vestibular schwannomas. The authors describe the clinical features of this entity in 6 patients, the histopathologic findings in 5 of them, and discuss possible factors predisposing to haemorrhage in these tumors. Detailed radiological and histopathological evaluation identified two factors which may be associated with higher likelihood of haemorrhage, namely preoperative radiation therapy and vascular abnormalities. Tumor size may not be a major risk factor for haemorrhage. Good outcomes can be achieved with microsurgical management. The histological features presented here differ clearly from findings in previously published case reports.

Intratumoral microhemorrhages on T2*-weighted gradient-echo imaging helps differentiate vestibular schwannoma from meningioma

BACKGROUND AND PURPOSE

Vestibular schwannomas (VS) may be difficult to differentiate from cerebellopontine angle (CPA) meningiomas. Demonstration of microhemorrhages in VS on T2*-weighted gradient-echo (GRE) sequences may have potential value to differentiate VS from CPA meningiomas.

MATERIALS AND METHODS

In this prospective study of 20 patients, MR imaging was performed with T2*-weighted GRE in addition to all basic sequences. Histopathologic examination was performed after surgery. Intratumoral hemosiderin was confirmed by pigment staining.

RESULTS

There were 15 patients in the VS group with 16 VS and 5 in the meningioma group with 5 posterior fossa meningiomas. Fourteen of the 16 VS and all 5 meningiomas were treated surgically and were confirmed on histopathologic examination. T2*-weighted GRE identified microhemorrhages on T2*-weighted sequence in 15 (93.75%) of the 16 VS. CT excluded calcification in all VS. T2-weighted turbo spin-echo (TSE) and fluid-attenuated inversion recovery (FLAIR) images recognized microhemorrhages in 2 cases. Pigment staining confirmed hemosiderin in all 14 surgically treated VS, and none of the meningiomas showed microhemorrhages on MR imaging. For the detection of microhemorrhages, T2*-weighted GRE showed a sensitivity of 93.8%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 83.3%. The sensitivity of T2 TSE and FLAIR for microhemorrhage was 12.5%. The Fisher exact test showed a statistically significant difference in the differentiation of VS from meningioma on the basis of detection of microhemorrhages (P < .01).

CONCLUSION

Most VS demonstrate microhemorrhages on T2*-weighted GRE. This finding is useful to differentiate VS from CPA meningiomas. T2*-weighted GRE should be used as a basic sequence to evaluate CPA tumors. Identification of microhemorrhages may have the potential to assess the aggressive biologic behavior of VS.

Intratumoral hemorrhage after remote subtotal microsurgical resection and gamma knife radiosurgery for vestibular schwannoma

Our report describes the occurrence of intratumoral hemorrhage in a vestibular schwannoma, which was treated with microsurgical resection thirteen years and gamma knife surgery (GKS) more than two years prior to the event. Although rare, it is apparent that bleeding into a vestibular schwannoma remains a possibility, even after the tumor has responded favorably to GKS. Long-term followup of patients with vestibular schwannoma who have been treated with GKS is advisable to assess treatment response and to detect adverse events (e.g. hemorrhage) suspected on clinical grounds.

Neuro-otological emergencies

PURPOSE OF THE REVIEW

Physicians find acute vertigo a diagnostic challenge. This article review recent evidence outlining the clinical presentation of acute central and peripheral dizzy syndromes and suggest when clinicians may consider acute neuro-imaging.

RECENT FINDINGS

Recent evidence highlights the difficulty that acute vertigo may sometimes pose to the clinician. For example, migrainous vertigo may have oculomotor abnormalities suggestive of either central neurological or peripheral vestibular dysfunction. Furthermore, vertebrobasilar stroke syndromes may mimic peripheral disorders such as vestibular neuritis, or when there is hearing involvement may be misdiagnosed as Meniere's disease. In addition to the need for identifying serious conditions in acute vertigo, recent evidence suggests that early steroid treatment in vestibular neuritis may improve long term outcome. Further trials regarding symptomatic outcome are required, however, before routine use of steroids can be recommended in this condition.

SUMMARY

Recent findings have not made the assessment of acute vertigo any easier for the nonspecialist. Although the commonest vertigo syndromes are benign, serious conditions such as stroke may masquerade as a peripheral labyrinthine disorder and conversely benign conditions such as migrainous vertigo may have clinical characteristics of central disorders. These findings re-emphasize the need for a thorough clinical evaluation of the acutely dizzy patient.