Distinct spontaneous shrinkage of a sporadic vestibular schwannoma

Documented Initial Growth Does Not Necessarily Indicate Treatment for Sporadic Vestibular Schwannomas

OBJECTIVE

To report the natural history of vestibular schwannoma (VS) who elected an initial period of observation and identify prognostic factors. To describe the natural history of growing VS, identify prognostic factors, and review the most recent literature.

STUDY DESIGN

Prospective cohort study and literature review.

SETTING

Tertiary referral center.

PATIENTS

Adult patients diagnosed with a VS between January 1998 and February 2023.

INTERVENTION

Magnetic resonance imaging surveillance.

MAIN OUTCOME MEASURES

Growth-free survival and subsequent growth-free survival considering significant growth as a change in size of ≥2 mm.

RESULTS

Of 430 patients undergoing observation with serial magnetic resonance imaging, 193 (44.9%) demonstrated significant growth at a median of 1.6 years (interquartile range, 0.94-3.51). Of the 193 patients who presented an initial episode of growth, 137 elected to continue to be observed. Of those, 83 (60.6%) presented a second episode of growth at a median of 1.43 years (interquartile range, 1.00-2.49). The subsequent growth-free survival rates (95% confidence interval) at 1, 3, 5, 7, and 10 years were 91.79% (87.26-96.56%), 64.44% (56.56-73.42%), 52.52% (44.23-62.35%), 42.23% (33.92-52.56%), and 36.11% (27.89-46.76%), respectively. Univariate and multivariate Cox regression analyses showed that EC tumor location and initial growth rate were significant predictors of subsequent growth.

CONCLUSIONS

Close observation after documentation of growth is an appropriate management in well-selected cases given that only around 56% of the tumor will continue to grow. Extracanalicular tumor location and initial growth rate are promising prognostic factors to help determine which patient would be a better candidate for close surveillance after initial documentation of growth.

Spontaneous shrinkage of vestibular schwannoma with the recovery of impaired hearing: A case report and literature review

Background

Sporadically occurring vestibular schwannomas (VSs) are the most frequent tumors in the cerebellopontine cistern and internal meatus and are commonly associated with hearing loss. These tumors have demonstrated spontaneous shrinkage rates of 0-22%; however, the relationship between tumor shrinkage and changes in hearing remains unclear.

Case Description

We report a case of a 51-year-old woman with a diagnosis of a left-sided VS and accompanying moderate hearing loss. The patient was treated with a conservative approach for 3 years, and the tumor showed a regression along with an improvement in her hearing ability during the yearly follow-ups.

Conclusion

The spontaneous shrinkage of a VS along with an associated improvement in hearing is a rare phenomenon. Our case study may support that the "wait and scan" approach is an alternative option for patients with VS and moderate hearing loss. Further investigations are needed to understand spontaneous VS regression and hearing changes.

Spontaneous regression of solid-cystic vestibular schwannoma: A case report

Background:

Vestibular schwannomas (VSs) are one of the most common tumors of the cerebellopontine angle and internal meatus, the evolution of this type of tumors is defined as unpredictable, it can enlarge or present a spontaneous regression as described in rare cases.

Case Description:

We report the case of a 50-year-old woman who presented with a large right full cystic VS revealed by a balance disorder associated with deafness in the right ear which spontaneously regressed. The patient was lost to follow-up for 3 years, the symptomatology improved, and the tumor clearly regressed without any surgical treatment.

Conclusion:

Spontaneous regression of solid-cystic VS is possible but rare, it can be part of conservative treatment, which requires regular follow-up.

Vestibular schwannomas with spontaneous shrinkage: about 35 cases

PURPOSES

The first aim is to describe the epidemiological, clinical, and radiological characteristics of regressive vestibular schwannomas (VS), based on volumetric measurements on MRI to define which regressions are significant. The secondary aim is to look for a correlation between a shrinkage of the tumor and the medical history, and the presence of clinical symptoms.

METHODS

We first selected all patients presenting with a VS who underwent two or more MRI of the internal auditory canal on the same 3 T MRI machine retrospectively between January 2013 and June 2018. All MRI images were evaluated independently by two radiologists. The volumetric analysis was performed contrast-enhanced 2D spin-echo T1-weighted sequence and expressed in cubic centimeters.

RESULTS

Thirty-five patients presented with a regressive VS on MRI (14%). The annual mean shrinkage rate was 0.08 cm³/year. Eighty percent of the patients present both a shrinkage by more than 0.01 cm³/year and a decrease of the initial tumor volume by more than 20%. The majority of patients are asymptomatic or presented moderate balance disorders, which remained stable or improved over time. Tinnitus was observed in 47% and was stable or improved in the majority of cases and the mean annual mean hearing loss was by < or = 4 dB/year.

CONCLUSION

Out of 247 VS, 14% decreased using follow-up (by > or = 2 MRI), and a spontaneous shrinkage greater than 0.01 cm³/year and greater than 20% could be considered significant.

Tracking Spontaneous Vestibular Schwannoma Regression with Volumetric Measurements

OBJECTIVE

To characterize a series of patients with MRI evidence of spontaneous vestibular schwannoma (VS) regression.

STUDY DESIGN

Retrospective case series.

METHODS

Retrospective review between 2012 and 2020 from a single, tertiary-care center of all patients with an untreated, sporadic VS and spontaneous regression in volumetric tumor size over the course of observation. The main outcome measures included VS size and location, presenting symptoms, medication use, changes in pure-tone averages and word recognition scores.

RESULTS

The 13 treatment-naïve patients (62% female, mean age 67.1 years) with spontaneous VS regression represented 3.9% of all patients undergoing observation with serial imaging during the study period. Median tumor size from initial MRI was 529.0 mm³ (range: 108 mm³ -13,180 mm³ ). The mean interval between MRI measurements was 5.5 years (SD 4.4 years). The average percent decrease in tumor size was 36.1% (SD 21.9%) and the average rate of volume decrease was 15.8 mm³ /yr (SD 25.4 mm³ /yr). Five patients were classified as having major regression, defined by a relative decrease in volume of >40%, while eight patients had minor regression (<40% relative volume reduction). No significant differences in initial tumor size, rate of regression, or audiometric changes were observed between the major and minor regression cohorts.

CONCLUSIONS

Patients with evidence of a spontaneously shrinking VS have a heterogeneous presentation. Due to the scarcity of this phenomenon, predicting which tumors will eventually undergo regression remains unclear. Employing volumetric measurements to compare serial MRI scans may improve the accuracy of detecting shrinking tumors.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E1647-E1652, 2021.

Incidental Effect of Long-Term Tacrolimus Treatment on Sporadic Vestibular Schwannoma Volume Shrinkage and Clinical Improvement

OBJECTIVE

We describe the effect of long-term tacrolimus delivery on sporadic vestibular schwannoma (VS).

PATIENT

A 48-year-old woman who was diagnosed a right VS.

INTERVENTION

Long-term tacrolimus delivery following liver transplant.

MAIN OUTCOME MEASURES

Clinical examination, audiometric test, and gadolinium-contrasted magnetic resonance imaging.

RESULTS

During the reported follow-up period, the patient felt hearing improvement especially in noisy environment. This was consistent with a clear audiometric improvement. Over a 26 months follow-up period, we noticed a 50% volume regression and a 40% decrease in the intensity of enhancement of the tumor after gadolinium injection.

CONCLUSION

Tacrolimus, an immunosuppressant used to prevent rejection in organ transplant, could lead to VS volume shrinkage and hearing improvement. Tacrolimus could be an interesting new therapeutic weapon, especially for VS in Neurofibromatosis type 2.

Decision Making in the Wait-and-Scan Approach for Vestibular Schwannomas: Is There a Price to Pay in Terms of Hearing, Facial Nerve, and Overall Outcomes?

BACKGROUND

The wait-and-scan modality has emerged as an important strategy in the management of vestibular schwannoma (VS) as it has been demonstrated that many tumors grow slowly or do not show any growth over long periods.

OBJECTIVE

To analyze long-term outcomes of wait-and-scan in the treatment of patients with VS, discuss the factors contributing to the decision making, determine the inherent risks of the policy, and compare our results with literature.

METHODS

In total, 576 patients with sporadic unilateral VS who were managed with wait-and-scan were reviewed retrospectively. Of these, a subset of 154 patients with 5-yr follow-up was separately analyzed. The tumor characteristics including patterns of growth, rate of growth, hearing outcomes, and likely factors affecting the above parameters were analyzed.

RESULTS

The mean period of follow-up was 36.9 ± 30.2 mo. The mean age was 59.2 ± 11.6 yr. Thirteen different patterns of tumor growth were observed. Eighty-four (54.5%) of 154 tumors with 5-yr follow-up showed no growth throughout 5 yr. Fifty-six (36.4%) tumors showed mixed growth rates. Only 57 (37%) patients had serviceable hearing at the start of follow-up, but 32 (56.1%) maintained it at the end of follow-up. One hundred fifty (26%) of the 576 patients who failed wait-and-scan had to be taken up for surgery.

CONCLUSION

While there may be no price to pay in wait-and-scan as far as hearing is concerned, this may not be the case for facial nerve outcomes, wherein the results may be better if the patients are taken earlier for surgery.

Spontaneous shrinkage of vestibular schwannoma

Background:

“Watch, wait, and rescan” (WWR) has an established place as a successful management option for a significant proportion of vestibular schwannomas (VS) as an alternative to microsurgical removal or stereotactic radiotherapy. VS may grow slowly and continuously, followed by stagnation or even shrinkage. We present two case reports of spontaneous shrinkage of VS along with a review of the literature.

Case Description:

A 29-year-old female presented with a progressive history of visual blurring and intermittent diplopia over 2 months. A 29 mm of maximum intracranial diameter (ICD) VS with secondary obstructive hydrocephalus was diagnosed. The patient underwent a ventriculo-peritoneal shunt with resolution of her symptoms and opted for initial WWR management. Interval scanning between 2007 and 2014 showed progressive reduction in the maximum ICD together with reduction in the degree of central tumor enhancement. Maximum ICD at most recent follow up was 22 mm. A 28-year-old female was referred with right sensorineural deafness. A right VS of maximum ICD of 27 mm was diagnosed. Initial WWR management was planned after discussion. Serial imaging showed an initial increase in the size of the tumor followed by progressive reduction in size. The most recent follow up showed a maximum ICD of 20 mm.

Conclusion:

Early WWR management can be associated with spontaneous shrinkage of VS over time. Prospective clinical study of larger numbers of such cases using the UK VS database may help to identify predictive factors for the spontaneous regression of VS.

Natural history of vestibular schwannoma growth and hearing decline in newly diagnosed neurofibromatosis type 2 patients

OBJECTIVE

To determine the rate of growth in vestibular schwannomas and the rate of hearing decline in neurofibromatosis type 2 (NF2) patients not undergoing active treatment

STUDY DESIGN

Prospective study.

SETTING

Data were collected at 10 NF2 centers, including hospital-based, academic, and tertiary care centers.

PATIENTS

120 NF2 patients with 200 vestibular schwannomas.

OUTCOME MEASURES

Hearing decline, defined as a decrease in word recognition score outside the 95% critical difference compared with baseline, and radiographic progression, defined as a 20% or greater increase in tumor volume compared with baseline.

RESULTS

During a total of 313.4 patient-years of follow-up, the rate of hearing decline was 5% at 1 year, 13% at 2 years, and 16% at 3 years; the rate of tumor progression was 31% at 1 year, 64% at 2 years, and 79% at 3 years. For this cohort, the median time to tumor progression (14 mo) was significantly shorter than the median time to hearing decline (62.0 mo).

CONCLUSION

These data provide potentially useful information for the design of clinical trials for NF2 vestibular schwannoma.