Multiple faces of children and juvenile meningiomas: a report of single-center experience and review of literature

Stereotactic Radiosurgery for Meningiomas in Children and Adolescents: An International Multi-Institutional Study

BACKGROUND AND OBJECTIVES

Meningiomas in children are uncommon, with distinct characteristics that set them apart from their adult counterparts. The existing evidence for stereotactic radiosurgery (SRS) in this patient population is limited to only case series. The objective of this study was to evaluate the safety and efficacy of SRS in managing pediatric meningiomas.

METHODS

Children and adolescents who had been treated for meningioma with single-fraction SRS were included in this retrospective, multicenter study. The assessment included local tumor control, any complications related to the tumor or SRS, and the emergence of new neurological deficits after SRS.

RESULTS

The cohort included 57 patients (male-to-female ratio 1.6:1) with a mean age of 14.4 years who were managed with single-fraction SRS for 78 meningiomas. The median radiological and clinical follow-up periods were 69 months (range, 6-268) and 71 months (range, 6-268), respectively. At the last follow-up, tumor control (tumor stability and regression) was achieved in 69 (85.9%) tumors. Post-SRS, new neurological deficits occurred in 2 (3.5%) patients. Adverse radiation effects occurred in 5 (8.8%) patients. A de novo aneurysm was observed in a patient 69 months after SRS.

CONCLUSION

SRS seems to be a safe and effective up-front or adjuvant treatment option for surgically inaccessible, recurrent, or residual pediatric meningiomas.

Pediatric Meningiomas: Current Insights on Pathogenesis and Management

Meningiomas are rare tumors in children, ranging from 0.4 to 4% of intracranial tumors. Differently from their adult counterpart, pediatric meningiomas (PMs) often show peculiar aspects such as the development of tumoral cysts, the involvement of the intraventricular space, and missing attachment to the dura mater. The most important difference with adults is represented by the high incidence of WHO grade II and III variants, which can account for more than 70% of cases. The prognosis of PMs mainly depends on the initial surgical resection because radiotherapy, which is the main treatment option in the case of tumor recurrence or progression, does not seem to increase the relapse free survival and the overall survival, and chemotherapy still misses specific and effective protocols.On these grounds, the need to better understand these tumors, to favor an appropriate multidisciplinary management, is particularly felt. The present review is focused on the advances on the pathogenesis, the molecular aspects, and the managements of PMs, with the goal to improve the knowledge of these challenging neoplasms.

Clinical features and long-term outcomes of pediatric meningiomas

OBJECTIVE

Pediatric meningiomas are relatively rare and have atypical clinical features compared to adults. The purpose of this work is to report our 15-year experience in the management of pediatric meningiomas and assess their clinical characteristics, pathological features, and prognostic factors.

METHODS

A total of 40 children (age ≤ 15 years) who were diagnosed as pediatric meningiomas were enrolled in this study. Patient information including clinical presentation, gender, age at time of diagnosis, histopathological features, tumor location, tumor volume, treatment methods, and follow-up data were extracted and analyzed.

RESULTS

The mean age at diagnosis was 10.78 ± 3.50 years (range 2-15 years) in 40 patients with a male to female ratio of 1:1.11. Headache, epilepsy, visual disturbance, and limb weakness are common clinical manifestations. Two patients had multiple intracranial meningiomas. Fourteen (33.3%) of pediatric meningiomas were high grade meningiomas. Seven patients (17.5%) were treated with STR, while GTR was achieved in 33 patients (82.5%). The mean follow-up period was 82.1 months (range 9-173 months). Recurrence occurred in 9 patients (22.5%), and 5 patients (12.5%) passed away.

CONCLUSION

The incidence of pediatric meningiomas increases with advancing age. In pediatric patients, the percentage of high-grade tumors is higher than adults. Younger children were more likely to have high-grade meningiomas, while patients with tumors located in skull base or parasagittal/falx tend to have low-grade meningiomas. The WHO grade III meningiomas were significantly correlated with poor prognosis. Adjuvant radiotherapy after surgery can improve prognosis and may be a potential treatment strategy in children with malignant meningiomas.

Pediatric meningiomas: 10-year experience with 39 patients

OBJECTIVE

The purpose of this article was to study the characteristics of pediatric meningiomas, including the clinical symptom, anatomic location, radiological finding, treatment approaches, and long-term surgical outcome as well as the possible influence factors of the prognosis.

METHODS

We retrospectively reviewed the medical records and follow-up data of 39 pediatric patients who were treated by operation for intracranial meningiomas in West-China Hospital between 2009-2019.

RESULTS

The incidence of pediatric meningioma was 0.74%. The mean age at surgery was 12.2 years and the ratio of male to female was 1.3. Three cases (7.7%) were related to neurofibromas. WHO grade I was found in 26 patients (66.7%) and higher grades was seen in 13 (33.3%). The most common location sites were convexity (35.9%). Gross total excision was achieved in 28 patients (71.8%). The mean follow-up period was 54.4 months. The recurrence rate was 41.9%. By survival analysis, only gross total resection (p = 0.028) was associated with favorable outcome.

CONCLUSION

Meningiomas in children are very rare and have a slight male predominance. Pediatric meningiomas are more commonly located in intraventricular and have higher incidence rate of high-grade than that in adults. Although being challenging, the gross total excision should be underdone to achieve a better prognosis.

The Role of Exosomes in Stemness and Neurodegenerative Diseases-Chemoresistant-Cancer Therapeutics and Phytochemicals

Exosomes exhibit a wide range of biological properties and functions in the living organisms. They are nanometric vehicles and used for delivering drugs, as they are biocompatible and minimally immunogenic. Exosomal secretions derived from cancer cells contribute to metastasis, immortality, angiogenesis, tissue invasion, stemness and chemo/radio-resistance. Exosome-derived microRNAs (miRNAs) and long non-coding RNAs (lnc RNAs) are involved in the pathophysiology of cancers and neurodegenerative diseases. For instance, exosomes derived from mesenchymal stromal cells, astrocytes, macrophages, and acute myeloid leukemia (AML) cells are involved in the cancer progression and stemness as they induce chemotherapeutic drug resistance in several cancer cells. This review covered the recent research advances in understanding the role of exosomes in cancer progression, metastasis, angiogenesis, stemness and drug resistance by illustrating the modulatory effects of exosomal cargo (ex. miRNA, lncRNAs, etc.) on cell signaling pathways involved in cancer progression and cancer stem cell growth and development. Recent reports have implicated exosomes even in the treatment of several cancers. For instance, exosomes-loaded with novel anti-cancer drugs such as phytochemicals, tumor-targeting proteins, anticancer peptides, nucleic acids are known to interfere with drug resistance pathways in several cancer cell lines. In addition, this review depicted the need to develop exosome-based novel diagnostic biomarkers for early detection of cancers and neurodegenerative disease. Furthermore, the role of exosomes in stroke and oxidative stress-mediated neurodegenerative diseases including Alzheimer’s disease (AD), and Parkinson’s disease (PD) is also discussed in this article.

Clinical features of newly developed NF2 intracranial meningiomas through comparative analysis of pediatric and adult patients

OBJECTIVE

NF2 patients can develop new meningiomas throughout their lifetime. Little is known about the clinical features of newly developed NF2 meningiomas. In this study, we analyzed newly developed NF2 meningiomas in a large patient population.

PATIENTS AND METHODS

Among 452 NF2 patients, the location patterns of 81 pediatric and 939 adult NF2 meningiomas were compared to find the predominant locations of newly developed meningiomas in adulthood. The clinical features of 39 newly developed meningiomas in 24 NF2 patients were summarized. Clinical risk factors of NF2 meningioma growth rates were analyzed.

RESULTS

Pediatric patients had significantly more intracranial meningiomas than adult patients at the skull base (except for the petrosal region) (p < 0.0063). Adult patients had significantly more cranial meningiomas than pediatric patients at the parasagittal, parafalcine (middle & posterior), and frontal/parietal/cerebellar convex surfaces (p < 0.0063). Newly developed NF2 meningiomas in adults tended to occur at different locations than the locations of NF2 meningiomas in pediatric patients. New meningiomas could develop at various ages. Ninety-five NF2 patients were imaged and followed up for at least one year. Twenty-four patients (25.3 %) developed 39 new meningiomas during the follow-up period. They usually had initial meningiomas when new meningiomas occurred. The number of newly developed meningiomas per patient and the petrosal location were significantly associated with both the absolute and relative annual growth rates (p < 0.05).

CONCLUSIONS

The number of newly developed NF2 meningiomas seems to be a clinical marker of NF2 disease severity. In adults, new NF2 meningiomas tend to occur in patients with initial meningiomas. The predominant locations of newly developed NF2 meningiomas seem to be the parasagittal, parafalcine (middle/posterior), and frontal/parietal/cerebellar convex surfaces.

Children's Cancer and Leukaemia Group (CCLG): review and guidelines for the management of meningioma in children, teenagers and young adults

Primary tumours of the meninges are rare accounting for only 0.4-4.6% of all paediatric tumours of the central nervous system. Due to the rarity of these tumours in children, and the consequent absence of collaborative prospective trials, there is no clear consensus on how the unique characteristics of paediatric meningiomas impact clinical status, management approach, and survival. Much of the evidence and treatment recommendations for paediatric meningiomas are extrapolated from adult data. Translating and adapting adult treatment recommendations into paediatric practice can be challenging and might inadvertently lead to inappropriate management. In 2009, Traunecker et al. published guidelines for the management of intracranial meningioma in children and young people on behalf of UK Children's Cancer and Leukaemia Group (CCLG). Ten years later we have developed the updated guidelines following a comprehensive appraisal of the literature. Complete surgical resection is the treatment of choice for symptomatic meningiomas, while radiotherapy remains the only available adjuvant therapy and may be necessary for those tumours that cannot be completely removed. However, significant advances have been made in the identification of the genetic and molecular alterations of meningioma, which has not only a potential value in the development of therapeutic agents but also in surveillance of childhood meningioma survivors. This guideline builds upon the CCLG 2009 guideline. We summarise recommendations for the diagnosis, treatment, surveillance and long-term follow-up of children and adolescents with meningioma.

Sporadic pediatric meningiomas: a neuroradiological and neuropathological study of 15 cases

OBJECTIVE Sporadic meningiomas have been classified in many different ways. Radiographically, these lesions can be described as occurring in either typical or atypical locations. The purpose of this study was to determine if there are any histopathological differences between sporadic meningiomas that arise in these varying locations in children. METHODS The neuroimaging, histopathological findings, and clinical records in patients with sporadic pediatric meningiomas not associated with neurofibromatosis Type 2 or prior radiation therapy were retrospectively reviewed. Tumors were classified by radiological findings as either typical or atypical, and they were categorized histopathologically by using the latest WHO nomenclature and grading criteria. RESULTS Fifteen sporadic meningiomas in pediatric patients were biopsied or resected at the authors' institution between 1989 and 2013. Five (33%) were typical in radiographic appearance and/or location and 10 (67%) were atypical. Four (80%) typical meningiomas were WHO Grade I tumors. Most (60%) of the atypical meningiomas were WHO Grade II or III. CONCLUSIONS This study is the largest series of sporadic pediatric meningiomas in atypical locations to date. Although sporadic meningiomas are relatively infrequent in children, those with atypical imaging, specifically those with apparently intraparenchymal and intraosseous locations, may be more common than previously recognized. In this study, pediatric sporadic meningiomas arising in atypical locations, in particular intraparenchymal meningiomas, may be of higher histopathological grade. The authors' findings should alert clinicians to the potential for more aggressive clinical behavior in these tumors.

Pediatric Skull Base Meningiomas: Clinical Features and Surgical Outcomes

The purpose of this study is to investigate the clinical, pathological, and prognostic characteristics of pediatric skull base meningiomas. A retrospective analysis of 44 pediatric skull base patients younger than 18 years who underwent surgery at Beijing Tiantan Hospital was performed. The study group included 20 males and 24 females. Multiple lesions were seen in 8 patients. WHO grade I was found in 28 patients and higher grade was seen in 16 patients. Recurrence or progression occurred in 10 patients after the initial operation. The overall survival rate in the follow-up period for the entire cohort was 89.7%. The authors found no sex predominance in pediatric skull base meningiomas. In addition, this lesion was more often seen in their second decades. In contrast to skull base meningiomas in adult patients, pediatric skull base meningiomas had a higher incidence of nonbenign histopathological variants and a higher rate of recurrence.

Delivery of Therapeutic Proteins via Extracellular Vesicles: Review and Potential Treatments for Parkinson's Disease, Glioma, and Schwannoma

Extracellular vesicles present an attractive delivery vehicle for therapeutic proteins. They intrinsically contain many proteins which can provide information to other cells. Advantages include reduced immune reactivity, especially if derived from the same host, stability in biologic fluids, and ability to target uptake. Those from mesenchymal stem cells appear to be intrinsically therapeutic, while those from cancer cells promote tumor progression. Therapeutic proteins can be loaded into vesicles by overexpression in the donor cell, with oligomerization and membrane sequences increasing their loading. Examples of protein delivery for therapeutic benefit in pre-clinical models include delivery of: catalase for Parkinson's disease to reduce oxidative stress and thus help neurons to survive; prodrug activating enzymes which can convert a prodrug which crosses the blood-brain barrier into a toxic chemotherapeutic drug for schwannomas and gliomas; and the apoptosis-inducing enzyme, caspase-1 under a Schwann cell specific promoter for schwannoma. This therapeutic delivery strategy is novel and being explored for a number of diseases.