Multimodal Management of Metastatic Malignant Meningiomas: The Role of Radiosurgery in Long-Term Local Control

A systematic review of extraneural meningioma metastasis: timing, evolution and outlook

PURPOSE

Extraneural meningioma metastasis is a rare occurrence and may pose a clinical challenge due to its unclear prognosis. In this systematic review, we analyze patient demographics, clinical characteristics, management strategies, and outcomes.

METHODS

PubMed, EMBASE, Scopus, Cochrane, and Web of Science databases were searched from inception to February 23, 2024 for cases of metastatic meningioma according to PRISMA guidelines. Descriptive statistics, Mann-Whitney U test, Fisher's exact tests, Kaplan-Meier curves, and log-rank tests were used for selected analyses.

RESULTS

A total of 288 patients (52% male) were included with an average age of 49 years at meningioma diagnosis. Tumors were distributed across WHO grade 1 (38%), 2 (36%), and 3 (26%). Most patients experienced intracranial recurrence (79%) and mean time to first metastasis was approximately 8 years. No change in WHO grade between primary and metastasis was observed for most cases (65%). Treatment of the initial metastasis was most often with surgery (43%), chemotherapy (20%), or no treatment (14%). Half of the patients were alive (50%) with an average follow-up of 3 years following metastasis. Overall median survival was 36 months for the entire cohort. This differed significantly between WHO grade 1 versus 2/3 meningioma primaries (168 vs. 15 months, p < 0.005).

CONCLUSION

Metastatic meningioma appears to be associated with more positive prognosis than other brain tumor types with extra-neural metastasis or metastasis in general. This is particularly true for cases arising from a WHO grade 1 meningioma.

Multidisciplinary approach to anaplastic and metastatic meningioma: A case report and review of the literature

BACKGROUND

Meningiomas are slow-growing neoplasms, accounting for 20% of all primary intracranial neoplasms and 25% of all intraspinal tumors. Atypical and anaplastic meningiomas are infrequent, representing fewer than 5% of all meningiomas. Unusually, they can show aggressive behavior, and extracranial metastases are extremely rare, representing approximately 0.1% of all reported cases.

CASE DESCRIPTION

Fifty-six-year-old male patient diagnosed with atypical basal frontal meningioma with multiple resections, both endoscopic endonasal and transcranial. After hypofractionated radiosurgery, the patient showed new tumor recurrence associated to right cervical level II ganglionic metastasis. We opted for complete resection of the meningioma and reconstruction with anterior rectus abdominis muscle flap, as well as selective cervical ganglionectomy. Anatomical pathology showed neoplastic proliferation of meningothelial cells in syncytial cytoplasm, oval or spherical nuclei with slight anisocariosis and hyperchromasia, and intranuclear vacuoles, all compatible with anaplastic meningioma.

CONCLUSION

Due to a lack of consensus on how to treat a metastatic malignant meningioma, this pathology requires a multidisciplinary approach, and treatment needs to be adapted to each particular case. Complete resection of the lesion is the primary goal, and this requires complex procedures involving endocranial as well as extracranial surgeries, which result in composite defects difficult to resolve. Microvascular free flaps are considered the gold standard in reconstructions of large skull base defects, with high success rates and few complications.

Surgical management of a giant hepatic metastasis from a cranial meningioma 10 years after resection

Meningiomas are the most common type of primary brain tumor; they have a low risk for extracranial metastases, which are primarily associated with increased tumor grade. Hepatic metastases from cranial meningiomas are extremely rare, with only a paucity of cases reported in the literature and no standardized approach to management. Herein, we report a case of an incidentally discovered giant (>20 cm) metastatic meningioma to the liver treated with surgical resection 10 years following resection of a low-grade cranial meningioma. This report also highlights the use of (68Ga) DOTATATE PET/CT as the diagnostic imaging modality of choice when evaluating for meningioma metastases. To our knowledge, this report describes the largest hepatic metastasis from a cranial meningioma to undergo surgical resection in the literature.

Tentorial Notch Meningiomas: Innovative Preoperative Management and Literature Review

Background

Tentorial meningiomas account for only 3–6% of all intracranial meningiomas. Among them, tentorial incisura (notch) location must be considered as a subgroup with specific surgical anatomy and indications, morbidity, and mortality. In this study, we propose an update on preoperative management in order to reduce postoperative deficits.

Methods

We retrospectively collected adult patients treated for incisural meningioma between January 1992 and December 2016 in two different neurosurgical departments. Demographic, clinical, and neuroradiological preoperative and postoperative data were analyzed. In the most recent subgroup of tumors, a preoperative digital simulation was performed to define a volumetric digital quantification of the tumor resection. A review of the pertinent literature has been also done.

Results

We included 26 patients. The median age was 58.4 years. Onset neurological signs were cranial nerve deficit in 9 patients, hemiparesis in 7, gait disturbance in 3, and intracranial hypertension in 3 patients. Simpson grade I removal was achieved in 12 patients, II in 10, III in 3, and IV in 1 patient. An overall rate of 23% postoperative complications was observed. The average follow-up duration was 68.5 months. Residual tumor was reported in 8 patients. Five patients underwent gamma knife radiosurgery. In 34.6% of patients, the surgical approach was chosen with preoperative digital planning estimating the potential volume of postoperative residual tumor, the target for radiosurgical treatment.

Conclusions

A multidisciplinary approach to plan incisural meningiomas management is important. To lower postoperative morbidity and mortality, a careful preoperative case analysis is useful. A planned residual tumor, supported by preoperative simulation imaging, could be safely treated with radiosurgery.

Molecular neuropathology of brain-invasive meningiomas

Invasion of brain tissue by meningiomas has been identified as one key factor for meningioma recurrence. The identification of meningioma tumor tissue surrounded by brain tissue in neurosurgical samples has been touted as a criterion for atypical meningioma (CNS WHO grade 2), but is only rarely seen in the absence of other high-grade features, with brain-invasive otherwise benign (BIOB) meningiomas remaining controversial. While post-surgery irradiation therapy might be initiated in brain-invasive meningiomas to prevent recurrences, specific treatment approaches targeting key molecules involved in the invasive process are not established. Here we have compiled the current knowledge about mechanisms supporting brain tissue invasion by meningiomas and summarize preclinical models studying targeted therapies with potential inhibitory effects.

Current experimental therapies for atypical and malignant meningiomas

INTRODUCTION

Atypical (WHO grade II) and malignant meningiomas (WHO Grade III) are a rare subset of primary intracranial tumors. Given their relatively high recurrence rate after surgical resection and radiotherapy, there has been a recent push to explore other adjuvant treatment options for these treatment-refractory tumors. Recent advances in molecular sequencing of tumors have elucidated new pathways and drug targets which are currently being studied. This article provides a thorough overview of novel investigational therapeutics including targeted therapy, immunotherapy, and new technological modalities for atypical and malignant meningiomas.

METHODS

We performed a comprehensive review of the available literature regarding preclinical and clinical evidence for emerging treatments for high grade meningiomas from 1980 to 2020 including contemporaneous clinical trials.

RESULTS

There is encouraging preclinical evidence regarding the efficacy of the emerging treatments discussed in this article. Several clinical trials are currently recruiting patients to translate targeted molecular therapy for meningiomas. Several clinical studies have suggested a clinical benefit of combinatorial treatment for these treatment-refractory tumors.

CONCLUSION

With numerous active clinical trials for high grade meningiomas, a meaningful improvement in the outcomes for these tumors may be on the horizon.

The Myth of Prometheus in metastatic meningioma to the liver: from craniotomy to hepatectomy

Metastases from intracranial meningiomas are rare, and among them, meningiomas with hepatic dissemination are extremely rare. Therefore, there are currently no guidelines for staging and treatment of metastatic disease in meningioma, a disease that is a challenge for both the clinician and the pathologist. Our literature review revealed 24 cases of liver metastases originating from intracranial meningiomas. We used them to analyze the pathological patterns of dissemination and to assess the different management strategies available, the most efficient and beneficial being surgery and chemotherapy, especially in the case of meningiomas with hepatic and∕or systemic dissemination.