Increased growth rate of vestibular schwannoma after resection of contralateral tumor in neurofibromatosis type 2

Case Report: Contralateral Progression of a Vestibular Schwannoma After Resection in a Patient with Neurofibromatosis Type 2

BACKGROUND AND IMPORTANCE

Bilateral vestibular schwannomas (VS) are a distinctive feature of neurofibromatosis type 2 (NF2) that result in a serious reduction in the quality of life for patients. The growth rates of these schwannomas are variable, and the early detection of increased growth is fundamental for improving outcomes.

CLINICAL PRESENTATION

A 17-year-old man with NF2 and bilateral VS presented with complete right facial paralysis and sudden right hearing loss less than 1 month after resection of a left VS. Imaging revealed rapid growth of the right VS with intratumoral hemorrhage, and the patient underwent urgent surgical resection with some improvement in symptoms.

DISCUSSION

Existing literature indicates a similar phenomenon after a longer post-operative period; however, none have shown such rapid symptomatology. Multiple etiologies were explored for this presentation, including the sudden decompression from the primary resection, paracrine factors, and hypervascularity from prior radiation.

CONCLUSION

VS resection in a patient with NF2 may be followed by rapid growth in the contralateral VS, leading to severe symptom presentation. Patients should be counseled regarding this risk to enable early detection and intervention.

Meningiomas in patients with neurofibromatosis type 2 predominantly comprise 'immunogenic subtype' tumours characterised by macrophage infiltration

Although recent molecular analyses revealed that sporadic meningiomas have various genetic, epigenetic, and transcriptomic profiles, meningioma in patients with neurofibromatosis type 2 (NF2) have not been fully elucidated. This study investigated meningiomas' clinical, histological, and molecular characteristics in NF2 patients. A long-term retrospective follow-up (13.5 ± 5.5 years) study involving total 159 meningiomas in 37 patients with NF2 was performed. Their characteristics were assessed using immunohistochemistry (IHC), bulk-RNA sequencing, and copy number analysis. All variables of meningiomas in patients with NF2 were compared with those in 189 sporadic NF2-altered meningiomas in 189 patients. Most meningiomas in NF2 patients were stable, and the mean annual growth rate was 1.0 ± 1.8 cm3/year. Twenty-eight meningiomas (17.6%) in 25 patients (43.1%) were resected during the follow-up period. WHO grade I meningiomas in patients with NF2 were more frequent than in sporadic NF2-altered meningiomas (92.9% vs. 80.9%). Transcriptomic analysis for patients with NF2/sporadic NF2-altered WHO grade I meningiomas (n = 14 vs. 15, respectively) showed that tumours in NF2 patients still had a higher immune response and immune cell infiltration than sporadic NF2-altered meningiomas. Furthermore, RNA-seq/IHC-derived immunophenotyping corroborated this enhanced immune response by identifying myeloid cell infiltration, particularly in macrophages. Clinical, histological, and transcriptomic analyses of meningiomas in patients with NF2 demonstrated that meningiomas in NF2 patients showed less aggressive behaviour than sporadic NF2-altered meningiomas and elicited a marked immune response by identifying myeloid cell infiltration, particularly of macrophages.

The Role of Extracellular Vesicles in Cancer-Nerve Crosstalk of the Peripheral Nervous System

Although the pathogenic operations of cancer–nerve crosstalk (e.g., neuritogenesis, neoneurogensis, and perineural invasion—PNI) in the peripheral nervous system (PNS) during tumorigenesis, as well as the progression of all cancer types is continuing to emerge as an area of unique scientific interest and study, extensive, wide-ranging, and multidisciplinary investigations still remain fragmented and unsystematic. This is especially so in regard to the roles played by extracellular vesicles (EVs), which are lipid bilayer-enclosed nano- to microsized particles that carry multiple-function molecular cargos, facilitate intercellular communication in diverse processes. Accordingly, the biological significance of EVs has been greatly elevated in recent years, as there is strong evidence that they could contribute to important and possibly groundbreaking diagnostic and therapeutic innovations. This can be achieved and the pace of discoveries accelerated through cross-pollination from existing knowledge and studies regarding nervous system physiology and pathology, as well as thoroughgoing collaborations between oncologists, neurobiologists, pathologists, clinicians, and researchers. This article offers an overview of current and recent past investigations on the roles of EVs in cancer–nerve crosstalk, as well as in neural development, physiology, inflammation, injury, and regeneration in the PNS. By highlighting the mechanisms involved in physiological and noncancerous pathological cellular crosstalk, we provide hints that may inspire additional translational studies on cancer–nerve interplay.

Clinical risk factor analysis of bilateral vestibular schwannoma's growth pattern inconsistency in individual NF2 patients

OBJECTIVE

Although bilateral vestibular schwannomas (VSs) in individual NF2 patients have the same NF2 gene mutation, they often show different growth patterns. We attempted to identify factors associated with this growth pattern inconsistency.

PATIENTS AND METHODS

Cranial MR images of 120 untreated VSs in 60 NF2 patients were carefully reviewed for their growth rates. Growth pattern analysis was performed on 68 VSs in 34 NF2 patients followed up for more than three years with at least three cranial MR scans.

RESULTS

Patient age and tumor volume were significantly associated with NF2 VS absolute growth rates (p < 0.05). Bilateral VS growth patterns in individual NF2 patients were the same in 18 (52.9 %) and different in 16 (47.1 %) patients. Patients with consistent bilateral growth patterns were significantly younger than the inconsistent patients (21.8 ± 5.8 years vs. 30.8 ± 13.1 years, p = 0.014). The bilateral VS volume consistency rates were significantly higher in patients with consistent growth patterns than in patients with inconsistent growth patterns (10/18 vs. 3/16, p = 0.028).

CONCLUSIONS

Patient age and volume consistency are the clinical risk factors for bilateral NF2 VS growth pattern inconsistencies. Bilateral VSs in young NF2 patients tend to have the same growth patterns. These findings may help us to predict the future clinical behavior of small NF2 VSs based on the past clinical history of the large ones.

Current Management of Large Vestibular Schwannomas for NF2 Patients in a National Reference Center

OBJECTIVE

Recently, treatment decision making for large vestibular schwannomas (VS) in patients with neurofibromatosis type 2 (NF2) has become increasingly challenging due to the availability of multiple therapeutic options including surgery, bevacizumab (an anti-VEGF), radiosurgery, and observation; and it often remains an arbitrary decision based on local practices without firm recommendations. Our objective is to discuss the multimodal treatment options for Koos IV VS in a national reference center for NF2.

STUDY DESIGN

Single-institution retrospective cohort study.

METHODS

All NF2 patients with Koos IV VS who visited our center, the National Reference Center for NF2 Rare Disease in Pitié-Salpétrière Hospital of Paris, between January 2016 and December 2018 were included. Clinical charts, radiology, operative reports, and audiograms were reviewed.

RESULTS

Among 54 NF2 patients with Koos IV VS (mean maximum extrameatal diameter: 34 mm; range:17-62 mm), 27 were operated on for 28 VS; 21 were treated with bevacizumab; and six were observed. In the surgical group, VS resections were gross total, near-total, subtotal, or partial in 32%, 25%, 32%, and 11%, respectively; and a good (House-Brackmann grades I-II) facial nerve function was achieved in 81.5% at 1 year. Hearing was preserved in 14%, 78%, and 66% of the surgical (n = 7), bevacizumab (n = 9), and observation (n = 3) patients, respectively.

CONCLUSION

All therapeutic options, including surgery and/or bevacizumab and occasionally observation, should be proposed to NF2 patients with large VS in the setting of dedicated centers. A decision-making tree is proposed for Koos IV VS management based on tumor evolution, hearing and clinical status of the patient, and contralateral VS size.

LEVEL OF EVIDENCE

4, case series study, historically controlled study Laryngoscope, 131:E98-E107, 2021.

Managing NF2-associated vestibular schwannomas in children and young adults: review of an institutional series regarding effects of surgery and bevacizumab on growth rates, tumor volume, and hearing quality

We reviewed our experience in managing of NF2-associated vestibular schwannoma (VS) in children and young adults regarding the effect of surgery and postoperative bevacizumab treatment. A total of 579 volumetric and hearing data sets were analyzed. The effect of surgery on tumor volume and growth rate was investigated in 46 tumors and on hearing function in 39 tumors. Long-term hearing follow-up behavior was compared with 20 non-operated ears in additional 15 patients. Sixteen operated VS were treated with bevacizumab. Mutation analysis of the NF2 gene was performed in 25 patients. Surgery significantly slowed down VS growth rate. Factors associated with a higher growth rate were increasing patient age, tumor volume, and constitutional truncating mutations. Immediately after surgery, functional hearing was maintained in 82% of ears. Deterioration of hearing was associated with initial hearing quality, larger tumor volumes, and larger resection amounts. Average hearing scores were initially better in the group of non-operated VS. Over time, hearing scores in both groups worsened with a similar dynamic. During bevacizumab treatment of residual tumors, four different patterns of growth were observed. Decompression of the internal auditory canal with various degrees of tumor resection decreases the postoperative tumor growth rates. Carefully tailored BAEP-guided surgery does not cause additional hearing deterioration. Secondary bevacizumab treatment showed heterogenous effects both regarding tumor size and hearing preservation. It seems that postoperative tumor residuals, that grow slower, behave differently to bevacizumab than reported for not-operated faster growing VS.

Management of NF2-associated vestibular schwannomas in children and young adults: influence of surgery and clinical factors on tumor volume and growth rate

OBJECTIVE

The authors' aim was to evaluate the tumor volume and growth rate of neurofibromatosis type 2 (NF2)-associated vestibular schwannomas (VSs) and the clinical factors or type of mutations before and after surgery in children and adults younger than 25 years at the time of diagnosis.

METHODS

A total of 579 volumetric measurements were performed in 46 operated tumors in 28 NF2 patients, using thin-slice (< 3 mm) T1-weighted contrast-enhanced MRI. The follow-up period ranged from 21 to 167 months (mean 75 months). Growth rate was calculated using a multilinear regression model. Mutation analysis of the NF2 gene was performed in 25 patients.

RESULTS

Surgery significantly (p = 0.013) slowed the VS growth rate from 0.69 ± 1.30 cm3/yr to 0.23 ± 0.42 cm3/yr. Factors significantly associated with a higher growth rate of VSs were increasing patient age (p < 0.0005), tumor volume (p = 0.006), tumor size (p = 0.001), and constitutional truncating mutations in the NF2 gene (p = 0.018). VS growth rates tended to be higher in patients with spinal ependymomas and in right-sided tumors and lower in the presence of peripheral schwannomas; however, no statistical significance was achieved.

CONCLUSIONS

Decompression of the internal auditory canal with various degrees of tumor resection decreases the postoperative tumor growth rate in children and young adults with NF2-associated VS. Patients with potential risk factors for accelerated growth (e.g., large volume, truncating mutations) and with increasing age should be monitored more closely before and after surgery.

Age-related schwannomatosis with potential exosome-mediated contribution to prostate hyperplasia: a case report and mini-review

A 72-year-old Caucasian man incurring a prostate hypertrophy presented with a right forearm nodule, the growth of which appeared to parallel the rise in his blood prostate-specific antigen (PSA) level. Echographic examination was consistent with a median-nerve schwannoma, and was confirmed upon magnetic resonance imaging (MRI). Excision of the nodule was readily performed without significant neural damage, and its schwannoma nature was confirmed upon immunohistochemistry analysis. Importantly, blood PSA dropped abruptly from ≈13 to ≈5 ng/ml within 2 months postschwannoma resection, a swift drastic reduction unachievable with oral dutasteride alone. However, 6 weeks later, a new nodule became apparent on the back of the left knee and was identified as a second schwannoma, thereby suggesting that its growth could have been stimulated by the resection of the first schwannoma, as previously described for vestibular schwannomas. The second schwannoma was in fact two: the bigger one was in the common fibular nerve and the smaller one in the tibial nerve. Both echography and MRI results were confirmed upon surgical resection of the bigger knee schwannoma. Although the third schwannoma has not yet been resected and formally characterized, we face a schwannomatosis case with an unexpected potential exosome-mediated stimulating effect on PSA secretion (PSA immunohistochemistry was negative on both schwannomas). On the other hand, preliminary genomic analysis showed a deficient balance for chromosome 22, the very chromosome carrying the three main genes involved in schwannomatosis. This age-related schwannomatosis case is thus discussed in light of the following: age-related DNA repair deficiency culminating in loss of chromosome/heterozygosity; CpG methylation/demethylation-based epigenetic aging; age-related functional decline of the immune system responsible for inefficient elimination of abnormal cells and subsequent tumorigenic cell turn-over; exosome-mediated pathologic intercellular communications; and prostate-invading brain neural progenitors as pathologic peripheral nervous system (PNS) cells.

Surgery of the lateral skull base: a 50-year endeavour

Disregarding the widely used division of skull base into anterior and lateral, since the skull base should be conceived as a single anatomic structure, it was to our convenience to group all those approaches that run from the antero-lateral, pure lateral and postero-lateral side of the skull base as “Surgery of the lateral skull base”. “50 years of endeavour” points to the great effort which has been made over the last decades, when more and more difficult surgeries were performed by reducing morbidity. The principle of lateral skull base surgery, “remove skull base bone to approach the base itself and the adjacent sites of the endo-esocranium”, was then combined with function preservation and with tailoring surgery to the pathology. The concept that histology dictates the extent of resection, balancing the intrinsic morbidity of each approach was the object of the first section of the present report. The main surgical approaches were described in the second section and were conceived not as a step-by-step description of technique, but as the highlighthening of the surgical principles. The third section was centered on open issues related to the tumor and its treatment. The topic of vestibular schwannoma was investigated with the current debate on observation, hearing preservation surgery, hearing rehabilitation, radiotherapy and the recent efforts to detect biological markers able to predict tumor growth. Jugular foramen paragangliomas were treated in the frame of radical or partial surgery, radiotherapy, partial “tailored” surgery and observation. Surgery on meningioma was debated from the point of view of the neurosurgeon and of the otologist. Endolymphatic sac tumors and malignant tumors of the external auditory canal were also treated, as well as chordomas, chondrosarcomas and petrous bone cholesteatomas. Finally, the fourth section focused on free-choice topics which were assigned to aknowledged experts. The aim of this work was attempting to report the state of the art of the lateral skull base surgery after 50 years of hard work and, above all, to raise questions on those issues which still need an answer, as to allow progress in knowledge through sharing of various experiences. At the end of the reading, if more doubts remain rather than certainties, the aim of this work will probably be achieved.

Connexin 43 maintains tissue polarity and regulates mitotic spindle orientation in the breast epithelium

Cell-cell communication is essential for tissue homeostasis, but its contribution to disease prevention remains to be understood. We demonstrate the involvement of connexin 43 (Cx43, also known as GJA1) and related gap junction in epithelial homeostasis, illustrated by polarity-mediated cell cycle entry and mitotic spindle orientation (MSO). Cx43 localization is restricted to the apicolateral membrane of phenotypically normal breast luminal epithelial cells in 3D culture and in vivo Chemically induced blockade of gap junction intercellular communication (GJIC), as well as the absence of Cx43, disrupt the apicolateral distribution of polarity determinant tight junction marker ZO-1 (also known as TJP1) and lead to random MSO and cell multilayering. Induced expression of Cx43 in cells that normally lack this protein reestablishes polarity and proper MSO in 3D culture. Cx43-directed MSO implicates PI3K-aPKC signaling, and Cx43 co-precipitates with signaling node proteins β-catenin (CTNNB1) and ZO-2 (also known as TJP2) in the polarized epithelium. The distribution of Cx43 is altered by pro-inflammatory breast cancer risk factors such as leptin and high-fat diet, as shown in cell culture and on tissue biopsy sections. The control of polarity-mediated quiescence and MSO may contribute to the tumor-suppressive role of Cx43.

Mechanism-based modeling of the clinical effects of bevacizumab and everolimus on vestibular schwannomas of patients with neurofibromatosis type 2

PURPOSE

To describe the natural growth of vestibular schwannoma in patients with neurofibromatosis type 2 and to predict tumor volume evolution in patients treated with bevacizumab and everolimus.

METHODS

Clinical data, including longitudinal tumor volumes in patients treated by bevacizumab (n = 13), everolimus (n = 7) or both (n = 2), were analyzed by means of mathematical modeling techniques. Together with clinical data, data from the literature were also integrated to account for drugs mechanisms of action.

RESULTS

We developed a model of vestibular schwannoma growth that takes into account the effect of vascular endothelial growth factors and mammalian target of rapamycin complex 1 on tumor growth. Behaviors, such as tumor growth rebound following everolimus treatment stops, was correctly described with the model. Preliminary results indicate that the model can be used to predict, based on early tumor volume dynamic, tumor response to variation in treatment dose and regimen.

CONCLUSION

The developed model successfully describes tumor volume growth before and during bevacizumab and/or everolimus treatment. It might constitute a rational tool to predict patients' response to these drugs, thus potentially improving management of this disease.

Factors influencing the growth rate of vestibular schwannoma in patients with neurofibromatosis type 2

BACKGROUND

Neurofibromatosis type 2 (NF2) is a devastating disease with no well-accepted management guidelines. Better understanding of the disease process provides the basis for how or when to initiate treatment. Only few studies have addressed the factors influencing the growth rate of NF2-related vestibular schwannomas (VSs), and these studies have reported variable results. This study aimed to assess the clinical factors influencing the growth rate of NF2-related VSs.

METHODS

The medical records of 66 patients (totalling 74 VSs) were retrospectively analysed. The tumours were measured according to a two-component box model. The tumour growth rate was estimated by linear regression analysis of the changes in VS volumes over time. The clinical characteristics of all the patients were recorded. The relationship between the tumour growth rate and clinical factors were analysed. Linear regression, Pearson's correlation and Student's t-test were conducted using the SPSS 19.0 statistical package.

RESULTS

The median follow-up duration was 4.9 years. The VSs growth rate was highly correlated with the initial VS volume (r = 0.97, p < 0.01). However, it was inversely correlated with the age at symptom onset (r = -0.41, p < 0.01). The average VS growth rate in patients with spinal tumours was 13.18 cm(3)/year compared with 0.19 cm(3)/year in patients without spinal tumours (p < 0.01). The VS growth rate in patients who had resection of a contralateral VS was slightly higher than that of patients with untreated VSs (p < 0.01). Other factors including sex, vestibular symptom, presence of other cranial schwannomas, family history and dermal abnormalities did not affect the VS growth rate.

CONCLUSIONS

The potential clinical factors influencing the VS growth rate are the age at symptom onset, initial tumour volume and presence of spinal tumours. Surgical resection of VSs might accelerate the growth rate of contralateral tumours. The effects of these factors require further experimental confirmation.

Rapid Recurrence of a Benign Meningial Perineurioma

BACKGROUND

We describe a rare case of a rapidly recurring benign meningial-based perineurioma. Clinical, radiologic, and pathologic features of a rapidly recurring falxial perineurioma are described; the perineurioma was discovered incidentally in an 86-year-old woman.

CASE DESCRIPTION

Due to progressive gait disturbances and radiologically proven progression after a 3-year symptom-free interval, subtotal resection of a large falxial-based meningeal tumor was performed.

CONCLUSIONS

The pathologic examination confirmed the diagnosis of a perineurioma (World Health Organization grade I). Follow-up magnetic resonance tomography 5 months later due to neurologic deterioration revealed an abnormally rapidly growing and extensive local tumor recurrence. Due to the mass effect, reoperation was performed and adjuvant radiation of 20 Gy to the tumor bed was implemented thereafter. Meningeal-based perineuriomas of the central nervous system are extremely rare, and literature on proper management is scarce. Although histologic classification reveals a benign lesion, follow-up may be considered for this type of tumor.

Neurofibromatosis type 2 vestibular schwannoma treatment: a review of the literature, trends, and outcomes

OBJECTIVE

Review the useful hearing preservation and tumor control outcomes of microsurgery (MS), stereotactic radiation (SR), conservative management (CM), and chemotherapy (ChT) for Neurofibromatosis type 2 vestibular schwannomas.

DATA SOURCES

Ovid MEDLINE was used to conduct a thorough search of English-language publications dating from 1948 to February 2013.

STUDY SELECTION

Patients must have had useful hearing at diagnosis and treated with one of the 4 treatments as their primary therapy. All sporadic vestibular schwannoma cases were excluded.

DATA EXTRACTION

A total of 19 articles were reviewed. Hearing preservation was defined as unchanged or improved useful hearing. Tumor control was defined as no change in size or tumor regression for SR, CM, and ChT-treated cases, and as no recurrence for MS treated cases.

CONCLUSION

Microsurgery seems to have the worse overall results, while SR has very good tumor control with poor useful hearing preservation. If a patient qualifies for CM, he is likely to show the most satisfactory results with the least treatment available. A close follow-up on ChT clinical trials and possible side-effects is warranted as preliminary short-term results are quite favorable. Additional long-term studies are required for a better understanding of this disease.

Conservative management of bilateral vestibular schwannomas in neurofibromatosis type 2 patients: hearing and tumor growth results

BACKGROUND

As new treatment modalities develop for the management of vestibular schwannomas (VS) in patients with neurofibromatosis type 2, it remains crucial to ascertain the natural history of the disease.

OBJECTIVE

To determine the relationship between hearing and tumor growth in patients undergoing conservative VS management.

METHODS

Patients harboring bilateral VS with at least 1 year of radiological follow-up were selected. Conservative management was proposed based on the small tumor size and/or serviceable hearing at presentation. Tumor size was calculated by using the 2-component box model and reported as mean tumor diameter. Hearing was evaluated by using pure-tone average and the American Academy of Otololaryngologists and Head and Neck Surgery classification.

RESULTS

Forty-six patients harboring 92 VS were included. The mean clinical and radiological follow-up times were 6.0 and 4.2 years, respectively. The mean tumor diameter was 13 mm at presentation and 20 mm at the end of follow-up. Mean tumor growth rate was 1.8 mm/year. During follow-up, 17 patients (37%) underwent surgery for VS. Surgery-free rate for VS was 88% at 5 years. The number of patients with at least 1 serviceable ear was 39 (85%) at presentation and 34 (74%) at the end of follow-up, including 22 (66%) with binaural serviceable hearing maintained. There was no statistical correlation between tumor growth rate and preservation of serviceable hearing. Tumor growth rates and age at presentation were inversely correlated.

CONCLUSION

This study illustrates the high variability among neurofibromatosis type 2 patients regarding hearing status and VS growth rate and justifies the choice of initial conservative management in selected cases.

ABBREVIATIONS

: AAO-HNS, American Academy of Otololaryngologists and Head and Neck Surgery classificationMTD, mean tumor diameterNF2, neurofibromatosis type 2PTA, pure-tone averageSDS, speech discrimination scoreVS, vestibular schwannomas.